I develop in .Net, WPF, and Javascript, and StackOverflow is a gem for these technologies. Not to mention there is a new version of .Net and WPF coming out every 2-3 years, and JavaScript is constantly evolving in form of frameworks and new browser versions (each with different support and intricacies). I don't see your argument as valid in my universe, and I also doubt that PHP and Python are most active technologies on SO.