Why dislike them? They've made a business decision to cater specifically to a niche of video producers. It's like complaining that a motorcycle repair shop won't work on your car.

Trying to use your analogy I would say its more like taking your harley-davidson to a general motorcycle repair shop who won't work on it because its not a "real" motorcycle.

They might say that but wouldn't the case be that they're not serving Harley because they can't get the proprietary screwheads for it?

In the case of games, the issue might've been IP and fair use. "Not art enough" in IP law means you might not be able to pass a fair use lawsuit for it.

I went back and found their original post[0]. It looks like they changed their stance in 2014 because video games were "no longer an outlier in our community nor a drag on our resources the way it once was".

[0] https://vimeo.com/blog/post/new-upload-rules

Isn't Twitch serving that niche now?

As far as I know, you still can't upload video to Twitch: they are focusing on livestreams. You can record your livestream, and then make it available to view, but well edited videos are rare (you'd have to make and edit the video, then stream it, then edit the VOD for length, etc)

Edit: found https://help.twitch.tv/customer/portal/articles/2577667-vide... which seems to indicate that you can upload video, but it seems to be rare on the platform compared to their bread and butter livestreams.

True but they store past live streams so you can watch old videos.

YouTube is still the king of "Let's Play" and edited-walkthrough formats.

That's true. Although not undisputed. Lots of great let's plays on Twitch. You don't have to watch live content. The video archive has tons of content on Twitch. So you can just go to the archive of your favorite personalities and rewatch their let's plays from months ago.

They also have a whole focused site for it - YouTube Gaming

I'm honestly surprised that's still going.