I don't really mind their unification efforts making me have to install a new app which for me on its own is only a minor annoyance and absolutely not worth getting at all upset about.

It's that they made no effort to bring over profiles and their associated watchlists, "continue watching" is my most used section of all the streaming apps (which they love moving every time I relaunch the app, but that's a different topic) and they didn't even apologize for essentially throwing away years' worth of tracking what the last episode I watched was.