I'm not saying to use what frameworks win in popularity. The problem is; how are you supposed to know which framework/library tool is going to be the best for your project without actually trying it in said project? I've heard a lot of stories of startups going down a path of using a new library because they initally thought it would be the right tool to fit their needs, but after actually implementing it they find it was the worst decision they ever made. They inevitably end up needing to rewrite everything (eventually) using the more appropriate tool.