It doesn't matter what the common use-case is. BitTorrent is better than traditional server->client downloads.
"Oh, pirates are the most common users of BitTorrent? But BitTorrent is better than traditional server->client downloads. More companies/people/whatever should be providing BitTorrent alternatives for downloading."
"Oh, pirates are the most common users of BitTorrent? But BitTorrent is better than traditional server->client downloads. It's a shame, but I guess we have to hinder BitTorrent traffic. Oh, what could have been!"
"Oh, pirates are the most common users of BitTorrent? But BitTorrent is better than traditional server->client downloads. More companies/people/whatever should be providing BitTorrent alternatives for downloading."
"Oh, pirates are the most common users of BitTorrent? But BitTorrent is better than traditional server->client downloads. It's a shame, but I guess we have to hinder BitTorrent traffic. Oh, what could have been!"