I have absolutely no problem with this. That's because I've only gotten one anon review and, oh guess what? It was a flame! Wow! What are the chances! If a reader is so lazy that they can't type in their e-mail address then, well, what kind of review are you getting? Granted yes, signing in was an optional thing for me too when leaving reviews, but I always left my name!
It is sad that some brianless twits with nothing better to do that harass people and their work have made this change necessary, but you know what? That's life. If people don't follow the rules as they are, then, there needs to be more rules. Sorry, kids.