Was Mahishasur actually a benevolent king who was slaughtered by a "temptress" Durga sent by the Aryans simply because he was dark and an aboriginal, a Shudra? This is the "alternative" view propagated by "progressive" leftist intellectuals, scholars and recently, by the JNU students. This is the Dalit, the lower caste version, they say, although I don't know how many Dalits are fine with the idea of Durga being a temptress rather than a divinity to be worshipped.
Even if you don't subscribe to this version of the Durga-Mahishasur episode in Indian mythology, the "progressives" say that we should be tolerant towards this view because this is just another view. Theoretically I am in total agreement. The problem arises when religions are not treated equally. Finding alternative versions of Hindu mythology is being progressive and tolerant, but finding alternative versions of Muslim historical characters is being insensitive and being Islamophobic. But that's another topic.
History and mythology, they say, is all about interpretation. Just as your interpretation makes Durga the divine mother who slaughters a demon called Mahishasur, there is another version that says that Mahishasur was the chief of an indigenous buffalo-rearing tribe. When the invading Aryans couldn't defeat him, they sent Durga as a temptress. She lured him and then slaughtered him.
This narrative tries to kill 2 birds with one stone: one, they try to prove that the now-discredited Aryan Invasion theory had some credibility, and two, they can strike at the Hindu community by reducing a revered deity into a mortal temptress who killed a valiant king with deceit.
Another narrative that makes the rounds is that the demons, the asuras, were actually tribal people in India, people of the lower caste who looked dark, a bit shorter, with curly hair. They are the ones who are depicted as demons, rakshasas and asuras. In Indian mythology, everything bad is represented by these physical attributes. On a side note, this isn't true just for Indian mythology. Villains in every folklore and even popular cinema look formidable, scary and not-pretty-looking.
Aryans, Kshatriyas and Brahmins on the other hand are shown to be noble, fairer, taller and even handsomer.
Religion is a strong sentiment. Want to insult someone, want to hurt someone, want to show someone lesser than the other? Attack his or her religion. Point of the negative sides of cultural and traditional norms even if these cultural and traditional norms are harmless, just to make people unsure of their identity, just to make them doubt their own beliefs.
Shudras and the people of lower castes, our Western scholars and Western-scholars-influenced scholars and intellectuals constantly say, were treated very badly. They were not even allowed to get educated.
If they were never allowed to get educated, how was Valmiki, a Bheel by caste, was not only able to learn Sanskrit, but also write one of the greatest epics in the world? Somewhere in Mahabharata the eldest Pandava brother Yudhishthira comments
The marks of a shudra are found in a Brahmin; but a shudra is not necessarily a shudra, not a Brahmin a Brahmin. In whomever a Brahmin's marks are found, he is known as a Brahmin and in whomever they are not found, him we designate as shudra.
Quoted from Rajiv Malhotra's Battle for Sanskrit.
This is a recurring thought appearing in various ancient Hindu texts, that a person's social attribute keeps changing according to his or her conduct. The one who follows the path of dharma is good and the one who follows the path of adharma is bad.
This trait -- what Yudhishthira says above -- is manifest in the biggest villain of the Ramayana, Ravana. He was a Brahmin. He had knowledge equal to 10 Brahmins. But his conduct was villainous, so despite being a Brahmin he turned out to be an asura. Contrary to the secular and Dalit beliefs (I'm using "Dalit beliefs" as a broad terms and I don't mean all Dalits subscribe to such views) that he was of a low caste hence he came to be known as an asura, he was a learned man blessed by Lord Shiva. He built a great empire, but people became so materialistic and arrogant that although they had knowledge and wealth in Lanka, they did not have wisdom.
In fact, whenever there's a battle between righteous humans and asuras it's because asuras are attacking innocent people, killing them, destroying their villages, and being villainous in general. You never come across an instance where asuras are attacked simply for existing.
Had Dalits and low castes been considered asuras and worthy of being slaughtered just for existing, the Ramayana would have been full of such episodes. If it was totally fine to harass the low castes, why turn them into demons and asuras and then bitch about them? Why not just bitch about them for being low castes? Why not say, "Oh, this is a Shudra village and it's our Aryan duty to plunder this village." In Islam, it's religious duty to convert, and if not convert, then plunder, kill, enslave and rape the non-Muslims, the infidels. What stopped Hindus to kill and plunder shudras and low castes as a religious duty? Why first convert them into horripilant rakshasas and demons?
Even vis-a-vis the battle with Ravana, it was Ravana who first abducted Sita. If you say Ravana abducted Sita to avenge disfigurement of his sister Shrupnakha, Shrupnakha was disfigured because she wanted to harm Sita because she thought because of Sita Ram couldn't be enamored by her beauty.
Another noticeable thing is Hanuman. Despite being a monkey, he was accepted as a divine god. After Ram, Hanuman is the most divine character in the epic. If Hindus back then were so stuck up about caste and stature, why would they accept a monkey as Ram's most trusted comrade? And not just Hanuman, Ram's army also had Jamvad, a bear, as a trusted commander.
If Valmiki was hell-bent on bringing in all sorts of animals (Jatayun was a condor) why couldn't he conjure up characters that were lions, elephants, panthers and tigers -- India had plenty of them. It shows what family you were born in and what were your intellectual or physical traits, weren't all that important.
A dhobi -- very low caste -- cast aspersions on Sita and Ram abandoned Sita. He could have easily incarcerated the dhobi instead of abandoning Sita, but he didn't, which shows even a dhobi had the ability to wreck havoc in the life of as powerful person as Ram. You may disagree with Ram's act of abandoning his beloved wife, but that's a personal trait and it has got nothing to do with the way women were treated in the society.
Before dying Ravana blesses Ram. Why would Ram, a relentless, shudra-slaying Aryan, would allow an Ravana, an asur to bless him?
Similarly, Krishna was raised by a cow-rearing family. He was a Yadav, a non-Aryan. Still, he was considered divine by Aryans and Kshatriyas even at that time. If caste lines were drawn so strongly, no matter how divine and prodigious, Krishna would have never been accepted as someone of a high stature. Both Pandavas and Kauravas respected him. It's not a Brahmin or a Kshatriya that reveals the universal wisdom through Gita, it's a Yadav.
Even if he was by birth not a Yadav, recall that he was Kansa's nephew, and Kansa is more vicious an asura than even Ravana. So if it was birth-related, wouldn't that make even Krishna an asura?
I think we desperately need to put some records straight.