Accessibility and streaming. I don't always want to download an entire video, sometimes I just want to dip into it and see if I am interested. There are streaming modes for torrents available in some clients that try to prioritize what you need to stream, but they never have worked very well in my experience.
Giving up accessibility and mobile seems like the touch of death.
Not sure why you're being downvoted. I prefer to directly download long Youtube videos so I don't have to deal with the site's garbage flash and HTML5 video players, but I only do that after I've actually watched a minute or two to see if it's interesting. Some kind of a browser-based streaming option is practically required to have a Youtube-esque in-band discovery experience (a roundabout way of saying "click around and waste 30 more minutes than you meant to").
Not having to download a video/piece of music is exactly the problem that YouTube solved. Going back to this doesn't seem like the right answer to me and will likely cost you most of your audience. Furthermore, moving to torrents is hardly a solution for YouTubers who actually monetise their videos through the site.
The better solution, if you don't agree with their new comment policy, would be to migrate to another video site like Vimeo.
I only watch at home, so clearly I'm not the right person to ask about accessibility.
Streaming though... It obviously depends on the userbase, but I have downloaded feature length videos faster through bittorrent than youtube took buffering the first minute.
Another idea - maybe a middle ground would be pre-leeching episodes. I will want to watch them eventually, so might as well download ahead of time. Best of both worlds. Actually... that's exactly the kind of thing that would kill a centralized service like youtube, but would make a torrent-based service fly.
FWIW, when I distributed a feature film online a few years ago, I was very surprised to discover that our download numbers were 4x our streaming numbers, even given very short streams.
There are a number of reasons why that might have been in that particular case, but still, an interesting data point.
Giving up accessibility and mobile seems like the touch of death.