Exactly. In practice, modern torrent swarms have such an over-abundance of seeders that there is ample bandwidth for everyone. Consequently, the famed BitTorrent tit-for-tat algorithm as well as rarest-first piece selection strategy become a less important.

Update: It's also noteworthy that BitTorrent Inc.'s official torrent client (as well as the largest player by marketshare), uTorrent, offers sequential downloading, as well as selective file downloading. And the BitTorrent network remains very healthy.