Earlier quoted context omitted.
I'm not sure why they'd consider Threadripper for the Mac Pro. This machine fits into Epic's target cases and could possibly live up to the asking price of the whole package at that point. Given how the rest of the mac ecosystem is going, I'd only expect the most stubborn of professional communities pick this up (film editing folks seems to still buy the Apple hype).
Film editing kinda makes sense because there is probably a lot of lock in on the software for people who don't like the Adobe monthly charge BS.
Maybe there is a technical reason but the story I've gotten from people I know doing this is that they are looked down on if they're PC users. It could be that Apple's software is that much better but it seems much more likely that they're charging what they know they can based on the generally stubbornness folks have around their software and workflow. I partly can't blame them, if your job is in a creative space the last thing I'd want to do is constantly rework a workflow and deal with the machinery itself rather than the content and output.