I agree as well - there are good for internal tools and prototypes, but absolutely not for production sites. At the same time they are useful and save a lot of time we spend repeating ourselves writing code for the same ui elements and patterns. I've been hacking on a framework like these, but that's flexible and modular, so you can break it down and customize it as much as you need. I've used this in several production websites for large companies and you wouldn't even know it was there. Working on documentation : )