I don't think Microsoft will make the game worse, they have probably done a tons of reasearch about the game and the Community. The chanes of Microsoft ruining the game are very slim because Microsoft KNOWS how much income they can get out of this game as long as they don't ruin MC.
Next, the Youtubers... people are worried that Youtubers will no longer be able to record MC content. That would be beyond stupid of Microsoft to do that, Microsoft isn't stupid, they won't dis-allow Minecraft content on Youtube because they know the Majority of people that buy this game is because of Youtubers. Youtubers ADVERTISE this game for FREE, they won't pass up on that opportunity.
Third of all, to the people who actually think that you'll probably have to pay to change skins, resource packs, go to the Nether or whatever, that's not going to happen, Microsoft knows how much income MC generates, they're not going to implement that, otherwise that would be down right stupid of them.
TL;DR RIP Minecraft? Nah, Microsoft isn't going to spend 2.5 billion bucks to sabotage a game.