How can you tell it's obnoxious if you don't know what it means? Easy to find out, though - http://en.wikipedia.org/wiki/Hype_cycle You might find it inaccurate or otherwise useless but it hardly seems obnoxious.

As to assessing Diaspora's chances of success - it's a perfectly reasonable thing to do, especially in a forum of technology-, product- and business-focused people. It's Hacker News, not Cheerleader News, after all. Just because a reasoned analysis might be negative doesn't mean it's cynical.