As mtmail said, there seem to be a lot of people that hate them. But then again, there's lots of people who hate BigCorp and its culture. There's lots of people who hate government IT and its culture.

I've been a software person for a long time, and I've learned that there's no perfect environment. Some are less toxic than others, though. And which ones are "less toxic" isn't necessarily a function of whether it's a startup (though there may be a higher fraction of people who don't know how to manage - or even how to be a grownup - in the start up world).

If you're in a reasonably sane and healthy environment, don't casually leave it. A better deal may be much harder to find than you think.