I don't see what the big deal is. I've seen rants, complaints, and even petitions online now about the change, and I quite frankly just have to laugh at it all. The same thing happens every time Facebook changes the slightest little thing about their layout. And guess what: people adjust to it! Not like they have much choice, but I think there are two main things behind the 'hate' for the new comment system:
1. People hate change, and hate having to adjust to change.
2. Internet mob mentality
These two combine to where a couple people are like 'OHGODCHANGE! BE AFRAID'. And suddenly everybody else is joining in that, and petitions get made, and it's just a big downward spiral of patheticness.
Needless to say, I don't really see the issue. Prior to this, I had a youtube account and a separate gmail/google+ account. Sure, it created a youtube account based off my existing gmail account, as well as a google+ account based off my youtube account. But it's easy enough to keep them separate. I can even be logged into the actual youtube account that I use, and open up gmail or google+ and be logged in with the actual account for those that I use.
I fail to see how it's forcing you to use google+ though. It generates an account based on your youtube account, yes. But nothing is forcing you to use any features of that google+ account...