In addition, I don't think there's anything wrong with watching bad shows, or having lots of people watch bad shows, or recommending really bad shows to others.
People chose to watch a movie or a series for all kinds of different reasons.
Most of the time, I imagine, they're looking to be entertained by high-calibre works in genres that interest them personally. If they'd like some recommendations on that front most people in this thread are perfectly happy to oblige and between our wealth of experiences and tastes we always manage to put together a fairly substantial list of shows to watch. This has gotten to the point where you very rarely see "Just getting into Anime" threads being made in the Off-Topic anymore, when they were once fairly common.
Still, there's more to watching a work than being 'entertained'. Sometimes you looking for a memorable experience that may also be entertaining. School Days, Mad Bull 34, Garzey's Wing etc all provide memorable, unique experiences to the viewer. That they happen to be 'bad' works in the traditional sense is of little consequence when you're looking to have singular, powerful experiences.
Finally, there's the communal aspect of watching and discussing an on-going series with a group of other people. Sometimes people will watch a show they might not even like just so that they can 'keep up' with the conversation at hand, this leads to 'hatewatches' where people ask questions like "why are you still watching this if you dislike it so much?". Clearly they must be getting something out of the work or they would not continue to watch it.