But it's sometimes very bad for the network. There are a few papers out there about how if too many people stream vs random download it can lead to bad performance.
Is this necessarily true if all of the connected peers are also streaming? In my understanding, Bittorrent optimizes for the most in-demand chunks, and in a streaming context those would be the ones at the beginning of the video.
It's actually the other way around. BitTorrent clients should prioritize that most rare pieces, there isn't really a notion of what the most in-demand pieces are.
If you were to combine streaming with a BitTorrent protocol that prioritized the most in-demand pieces you would probably not be able to watch most videos to the end without pauses to buffer or maybe even at all.
By prioritizing the most rare, even if all seeds left the swarm there's a much better chance swarm combined may still have all pieces and the torrent can still be finished.
