This strategy is mentioned in many bittorrent discussion.

What I have yet to see is any sort of justification for why it is ok to push personal risk onto other people, many of which have no idea how bittorrent works.

If you're going to use bittorrent for works that are protected by copyright, sharing in a small amount of risk is how the protocol works. Technical changes that actually reduce risks are fine; moving risk around is merely hoping someone who is ignorant of the technical details can be the patsy.

I'm not familiar with the specifics of the protocol, but your download speeds would be much slower without uploading. I believe that with BitTorrent, you are penalized/rewarded somehow for not uploading vs. uploading.

Not really, trackers will impose restrictions on users based on seeding ratios, but if you just DHT a random torrent whoever gets bandwidth is more down to random luck than priority towards other seeders. There is just no protocol level mechanism that prioritizes seeding to someone with a higher upload - the choice of who to seed to is up mostly to the implementation.