It's probably ignorance. Using a networks full upload bandwidth will stop everyone else from browsing. If people are using torrent programs with no throttles then you can expect this. I wouldn't think most routers do a very good job of allocating bandwidth for the internet, but who knows. Many still do not have QOS, and those home routers that do have few options. But only the network admin can solve this, and if there isn't one this problem will continue.