It also doesn't support a few pro workflows I don't understand (multiple camera editing, etc)... seemingly because the new interface is a radical departure. It uses a single, treelike track instead of multiple tracks, and doesn't easily map to these workflows. This to me feels like an "Innovator's Dilemma" situation: the new interface does many things overwhelmingly better, but has important regressions.
The regressions will be fixed or outweighed in time. For now (perhaps not for long) other software, including the previous version of Final Cut, compares favorably.
They needed to rebuild for 64-bit. This is what you get when you start over. I expect that patches and new plugins will turn it around by next year.
Lost in all this is the incredible Motion 5 at $50. Learning that and selling some templates (with decent Parameter Rigs) for Final Cut Pro X users would seem to be a nice way to make some extra cash.
I actually don't think this is quite right. I'll quote Gary Adcock's Macworld review:
"Most of the features introduced in FCP X are welcome and badly needed. Some are long overdue. Still, others are positively jarring and require a change in mindset to appreciate."
There is no doubt that Apple made it unusable for high-end pros (for the time being, at least) but I feel they also added many things that high-end pros would have really appreciated, had they been able to use it seriously. So it's not quite as simple as "amatueurs only" (even if you're talking about advanced amateurs.)
They liked the new features and interface changes they saw, they liked the complete rewrite (64 bit, much faster, background rendering) and, most importantly, they didn't know which features would be missing.
The transition is just too rough.
Except, apparently, you can't buy FCP7 any more (at least that's what I've heard from one guy I know in the industry). Which means that if you're a Final Cut Pro house and need to hire more staff, I guess you're kind of stuck going the pirate route for getting editing software for your new employees.