I've had fans ask me to continue writing more books in that universe, and my answer is always the same:

Unless I have something as good as or better than what I've already written, I have no desire to write more in that universe.

I can't speak to Collins personally, but it's a little odd that after taking ten years off to turn her books into films, she went right back to the universe to start making more books that become films.

Again, that's great for her moneywise, and I don't begrudge anyone who wants to make a buck in an honest way, but from a creative standpoint, it's a little sad.