>And yet, sharing files is a very common use.

True, but it's not an intended use. Filesharing via IRC is implemented very hackishly, what with fserves and "credits" and all that crap. So any complaining about it, especially when there are perfectly fine alternatives like BitTorrent and Gnutella, just isn't valid, just like you can't whine that your email client sucks at FTPing.