Frameworks can sometimes be annoying. It's like learning a new sub-language on top of the programming language as there is a certain amount of familiarity you need with a framework's calls (ex. to program in Python, it goes a lot faster if you know that it's len(list) not list.length() and similarly if you're using Rails it's important to know that there is no validates_is_number, but there is validates_numericality_of). So, you start learning all these things that may or may not apply to your project - the language of the framework. And in some places it slows you down and you feel like there's abstraction just for the sake of abstraction, but in the end I think it's worth it.

I also think Joel misses something: most programmers are bad programmers. They'll dig you into holes, write lots of spaghetti string code, etc. At least when they're using a framework there's some constraint on their madness. Frameworks (generally) make it a tad difficult to work outside of their constraints and so the default becomes to work in that standard way. So, you don't get people doing weird things as often - like building a string that is the page that they'll echo out like the piece of PHP I'm working on today does (guess they didn't realize that you could simply go out of PHP mode to do that).