Pros were grumbly about change for about 6 months. It became fuel for the anti-Apple crowd and was blown way out of proportion as usual.
The initial release was rough as well for some shops due to missing features, but pretty much all of what the needed came back within the first 6-12 months. And being that there was never a forced upgrade, the older version continued to work fine in the meantime. I think many threatened to leave, but never did, while only a handful really did make the jump to Adobe. Apple also admitted their hardline approach with the release of Final Cut X was a bit rough. But people wanting to bash them ignored it and clung to the "they are smug assholes" line as usual.
Adobe on the other hand has pissed off a lot of smaller shops with the whole creative cloud situation, and requiring a $600 a year investment per person for the video side. Apple still has the advantage of not needing to move to such a service since they have revenue from both the hardware and software. And less work on the software is needed due to the technologies built into macOS. Adobe has to put in a lot more work to bring their products to both Macs and Windows, necessitating such a subscription model.
Pros were getting very nervous over the hardware situation though. The recent announcements seem to have given the community a lot of optimism. I know in particular one Mac hardware hacker in Hollywood has been keeping a lot of pre 2013 Mac Pros going with newer GPUs, with a fair amount of his business going to Final Cut houses. Never got around to sending him my NVidia 970 to be modded for boot screen support, and now not going to bother with the good Apple news.https://forums.creativecow.net/thread/335/82256
is a good thread from 2015 from someone wondering why curmudgeons were still clinging to anger over change instead of getting over it. Browse around there and you'll see folks excited about where Apple is going again heading into NAB Show later this month.
Apple continues to showcase examples of Final Cut X usage here: https://www.apple.com/final-cut-pro/in-action/
and at their yearly WWDC conference.