Everyone reacted the same way they react whenever Apple does something like this.
Apple III, Apple Lisa, Macintosh, Final Cut Pro 1, iMovie, iTunes, OSX 1.0, iPhone, iMac, iPad...
Look at the reactions from their customers... absolute outrage, then 2 years later, you can't pry it from their cold dead hands. You can't make a huge change like this and expect a fully formed product... but Apple is really good at releasing software that will be adapting to the needs of the users in relatively short order. What they've achieved in a short development cycle with FCPx is amazing - and very mac like... the interface is now approachable by the general user, and all of the power tools are neatly tucked away. 90% of your day is at your fingertips... and that which isn't is being addressed (note: in the order they're being asked for most vocally by the professional users who they apparently don't listen to) will be shortly based on the user need. If they had converted everything straight off, the huge code purge wouldn't have happened (and it needed to). Soon, we'll end up with a system that is exactly what we need if we just continue letting apple know what we need addressed.
FCP's old code base was at the end of its life. It was originally Adobe's pre - premeire attempt at a video editing package that was then sold to Macromedia... after years of primary development by a non-Apple team, it got purchased by Apple and the development team along with it. It didn't adhere to the old Apple interface rules (pre-osx), much less the new ones from the next/osx world. I'm so happy that they are doing this overhaul. the optimizations in it for each new main processor platform it's been released on have weighed it down (and that was initially on an entirely different architecture - PPC // before that, it had been developed on 68040 processors).
Much like the PPC itself... they couldn't take it farther due to all the legacy code within the app. they also had rolled in so many apps to the studio package whose primary functionality can now be contained directly within the FCP interface that the process of approaching Final Cut Pro as a novice at all was nearly inconceivable. The new tool can be learned by a child with almost no adult interaction... and the complex tools are still in there, they're just hidden. This is a VERY Apple mindset - I'll be installing some POSIX compliant, open source XWindows GIS applications from within terminal later tonight... if you know what those are, you know how to get to those features of the MacOS... if not, you don't need to know and the way to do that is hidden from view.
I spent years in OSX dealing with console based sys admin and network admin tools... not at all the "lickable, toy interface" that was touted at the beginning of the OSX lifecycle -- and I've been doing that from within OSX since Developer Preview 4 (pre release in 2000).
All of the power we'll need in FCP will be there if it's not already... they're just getting started, and in 2-3 years, we'll most likely see a huge change in the normal workflow of the Hollywood establishment driven by the fact that Apple DOES respond to their users, but sometimes requests for a band-aid being removed are followed by a brief stretch of pain.
The past 3 versions, the users have been crying for apple to make all of the changes they just made -- now when they do it, the users whine because they don't have the old system anymore.
)... I can't wait to see what they have in store.