Well, you don't go to a surgeon and make him explain why he has to use the tools he uses. If I'm hired as an outside consultant in my area, I don't take a new

Well, you don't go to a surgeon and make him explain why he has to use the tools he uses. If I'm hired as an outside consultant in my area, I don't take a new project unless it uses the tools that I think will minimize risk. It's better to reject the micromanaging client, who doesn't know shit about your field, than to accept the offer, fail, and screw up your reputation. Luckily, so far there was only one client who tried to force me to use blocks of modems instead of scaling Skype addins. He also wanted me to work for free for first several weeks. Needless to say, I didn't continue the conversation after two strikes. This principle also applies to RoR/Django vs J2EE. If you are an expert, you get to make decisions. If they have legacy code written that's a completely different story, of course.