From random people, it's not usefull for sure. But, I think doing +1 or thumb up when you are contributing somehow to the actual project is actually valuable to gauge support.
It's actually awful. Often times everyone pretty much agrees a change is needed. It needs a bit of work which needs to be discussed.
The +1s are so irritating because you have to read through a huge conversation and you also keep getting email notifications because you want to keep in touch with a thread. It actually makes it harder to do what the github topic is about with the +1s.
I think everyone agrees gauging support is valuable. The issue is that the mechanism should be an up/down voting feature like HN has, not a post in a thread meant for conversations.
