Like some others mentioned, I haven't seen this issue either (yet anyway) While I do have a G+ I tested this out by signing out my Google and thus signed out of YouTube. I went to a video and didn't see anything about G+, it showed the thumbs up/down, and when I went to click it just popped up below saying "sign in or sign up" directing to sign into YouTube, not G+... which is normal. Almost every comment board site makes you sign in in order to comment or rate it's content. Perhaps this is something they've either corrected in the last day since you posted about it, or they haven't rolled it out entirely yet... I don't know. I do know I haven't seen the issue though. Good luck to you sir and getting them to change their ways. I like Google.. in fact I love Google and all the integration, but I agree it's stupid to make somebody sign up for G+ to use YouTube.. 2 different services and one should not be required to have an account with one to use the other. It's simply convenience when they link them for those that actually do have both and want them connected.