I assume the barrier to this is the enormous amount of bandwidth needed to support such a download.
Instead of putting the load directly on one server, using BitTorrent, it's distributed over the community at large.
Yes, some ISPs are throttling BitTorrent, which is unfortunate because it's a completely legal method to download and share files. The whole issue surrounds the content of the files. Since ISPs would be sued into the stone age if they started filtering content, they chose to do something about the protocol instead, and that, of course, is a hot topic of debate.
That being said, even if an ISP is throttling your bandwidth to, say, 20 kb/s at all hours of the day, the data dump can be downloaded in less than half a day. For anyone wanting to download this stuff, it's not a big deal to leave your computer on overnight.
I would say that an official HTTP host of this content is unnecessary, although certainly not undesirable if it were available. And as Jeff mentions, users are free to host the files however they want after an original copy is obtained.
Alternate solution: PayPal me $5 and I'll send you a copy on a DVD. :)