From what I have read online, I would say that very few people in news media are blaming the farmers' protests (at least in international coverage), even though those protests are longer-lasting and larger gatherings than most of the others. What I am mostly seeing is Western liberals blaming the conservative government of a developing nation by pointing at election rallies (which only took place in a few states and were held by all parties), religious events (because liberals are often anti-religion or Hinduphobic), or the government (who actually has been highly competent in managing the pandemic overall).
I don't think there is enough evidence (yet?) to call any one factor a "key contributor". We simply don't know. People in India were increasingly mobile as their pandemic conditions improved into a low steady state (https://ourworldindata.org/grapher/changes-visitors-covid?co...). I am guessing that some combination of the things you listed, plus general increase in mobility, plus some new variant of the virus that spreads more easily, is what led to this situation. India went from normal conditions to hitting the previous peaks within a month, and that feels like something more than just a few isolated events.
> This situation is really a reflection of the selfishness of the people.
That might be fair to say in a developed nation that is wealthier. But in many other nations, people simply need to work or go to places where they are around other people. They don't have the infrastructure, wealth, and luxury of remote work or delivery services to just avoid society altogether or reduce society-wide mobility. They also don't have the same amount of home entertainment choices like streaming services or expensive video game consoles or whatever else. I imagine shutting down cities is a much more significant challenge in places that are denser than, for example, American cities, but without the same economies, standards of living, disposable income, and so on.