Knives can be used to stab people...should we therefore stop selling kitchen knives? That's pretty much the argument against Google - it can be used for illegal purposes, just like almost anything can be misused. You're not really misusing TBP if you use it to obtain illegal content, because that is its use. The point to make here is that common sense has been applied to the situation. Yes, the sods at TPB can argue that they're not technically doing anything illegal, but everyone knows the website is pretty much designed to facilitate illegal content, and nothing much else.
Now, I'm not normally one to argue against such sharing websites. It's just the audacity these guys have; they're pretty much incapable of seeing what could be wrong with what they're doing, and constantly using technicalities to evade punishment. They're bloody annoying tbh.
Of course torrents aren't illegal, but torrent files that direct your client to illegal content are bound to attract the attention of the law, and TBP's existence is pretty much to distribute these files.