I think people want to support their friends, optimistically encourage development in the community, and root for things that are trying to bring to them what they want to see. There are plenty of folks out there, that love the announced and teased vocals, and therefore are excited about a project that promises to bring that to them.
Where communication breaks down I think has more to do with the condition of the internet as a social space. By hyping them up are you "blindly supporting them" or just being positive? By pointing out inadequacies and inconsistencies, are you productively contributing to the discussion or are you being a "hater"?
I agree with Blue that it is somewhat of a popular opinion here because many of us are old. Old in the sense of... internet exposure, of course. You see the same kinds of stories, the same kinds of people, and the same kinds of events play out over and over again over the years. But hopefully everyone can take a step back and appreciate both deserved positivity, and deserved questioning. (And hopefully abstain from wanton dunking-on and incredulous hype alike.)