I did. I also asked the same Q when I helped catch Cheetah Mobile and Kika Tech doing ad fraud: https://www.buzzfeednews.com/article/craigsilverman/android-...

And when I busted a large ad fraud scheme of dozens of apps: https://www.buzzfeednews.com/article/craigsilverman/how-a-ma...

In all cases Google basically said it takes action against specific apps found violating policy. It seems unwilling to take action against a developer as a whole and ban them. I would also add that I suspect the Play store is not equipped to enforce a ban. People can easily create a newco and get back into the store. This is definitely a much larger issue. So I think that among other things these stories show that you can be a clear bad actor and still do business in the Play store.