(I have lots more to say on this topic - even more so than other topics. But I'm going to sleep now and can't finish this :( )
1) There are a lot of crappy startups right now.
2) People are bad at choosing which businesses will take off, but think they are good. Accelerators could easily turn into a big circle jerk, but more insidiously, a place where startups that make the bosses happy get resources. Often innovative startups are frowned upon because new ideas are hard to understand;
3) Accelerators have mixed success. Here's an Economist article - http://www.economist.com/news/special-report/21593592-biggest-professio…
Here's something I texted to my roommates a few days ago:
"Unless your idea is absolutely brilliant, I don't think startups are about ideas. I think they're about copying other ideas and doing... Wait for it... actual market research to figure out e.g. where or show to sell the stuff"