For me whether or not to use a permissive license for a personal project is pretty easy: if I'm writing a library or trying to promote an open standard, then it

For me whether or not to use a permissive license for a personal project is pretty easy: if I'm writing a library or trying to promote an open standard, then it'll probably be in my interests that a lot of people use it in their own projects, even if I don't get to see exactly how, so I'll try to make it MIT/BSD licensed. If the code I'm writing is supposed to be an user-facing "finished" product, then it'll probably be in my best interests that if people want to make something based upon it that I'll be able to see some of that work, so I use (A)GPL. Has worked pretty well for me so far, I still believe that the copyright system, and indeed IP law in general is deeply flawed and in dire need for reform, but that's how I make do for now.