Editors are cranky old farts...
And I am one of them. There are some glaring issues (No DVD Studio? Really?!) but anyone who starts a commercial editing project on software that was just released is a HUGE idiot. I'm looking forward to the upgrade (holding off until 10.6.8 comes out like the recent tech bulletin recommended) but all my current projects are in FCP 7, and will stay there. I have some toy projects I will be doing in FCP X as soon as I get it, but anyone who is doing for-pay work on brand new software... I feel for their clients, and hope to steal them away.
If this was Adobe, or Avid, or Joe's Software Haus, there wouldn't be one tenth the butthurt about the software. But everyone is primed to kvetch about Apple. We'll likely see an entire software ecology built up around the new release, addressing shortcomings and adding features. Calling it a failure the day it was released is.. very typical of people who complain about Apple.
It'd be like calling the iPhone a failure because it didn't have copy-paste. Oh, wait, they added that.