The modern hate for Minecraft stems from a lot of different factors, but honestly I think much of it can be simplified to "this game is way too popular and has a trash fanbase full of immature kids".
Which is stupid because that's essentially claiming that the game on it's own and everything about it is bad all because of the people who play it, and/or the sheer amount of people who play it. You can't blame the game for any problems it's fanbase presents.
In recent years, I've seen tons of games (especially Indie ones) unfortunately fall victim to remarkably similar kinds and amnounts of incessant hatred. TV Tropes has an article for this situation, they've termed it "It's Popular, Now it Sucks!". Yes, you're perfectly free to have your own opinions, there's nothing wrong with not liking a popular piece of media on it's own, I shouldn't even have to explain that you're entitled to have your opinions. But what is wrong is shoving your hatred of the game down people's throats the minute someone brings it up or states they like it, as well as associating anyone who plays it with the "immature brat" stereotype that a lot of people hold in regards to the game's fanbase. Not only is that completely unfair, it's also entirely hypocritical to call the fanbase "immature" or "toxic" when you're going around spouting insults and rage over the game and it's fanbase at the drop of a hat.
I'm not accusing anyone here of exhibiting this particular behavior, but all around the 'net I've seen countless people who do act like that, and chances are most of you have as well, at least at one point. Personally, I'd advise doing everyone a favor, and that includes yourselves, and consider being a little more open-minded about the game, as well as the possibility of Steve getting in Smash, if you're not already. The game and it's fanbase get way more than enough hate and backlash as they are. Nothing good will come from contributing to it.