The post mentioned slow downloads. Complain about the speed of http based downloads if you cannot use bittorrent. Or maybe the size of the patch. 1.2G? WTF?
I'm old. Get off my lawn.
If bittorrent doesn't work because my ISP is blocking it, why would I complain to Blizzard about it?
For companies like those, distributed downloads take a massive load off the central servers while allowing machines that are closer to the client to assist in the download process. If you made a 1.2 gig patch HTTP only for a few million users... I would need to research even how to size that pipe up.
Torrent is hated primarily because it is over used (by people that would never admit they are pirating or getting.. ahem their 47 Linux ISO's a week) and like any protocol out there, overloading it will cause it to lag or break.
Example in blizzard's case they modify their downloader from a stock bittorrent client in order to limit the number of sessions to reduce the change that crappy routers will bomb due to overload. They seem to really try to make it net friendly rather than some clients that open 5000 sessions a second. Properly used it is pretty useful.