It turned out I had used the word "dice" too many times in a description of my simple "dice" game because I described all the rules in the description. I had to mutilate my description and remove about 80% of the times I used the word "dice".
I emailed Google telling them what I had done, and that I fixed that problem, and that I really hoped that WAS the problem, and I begged them not to remove my apps because I was diligently trying to figure out what I had done wrong, and that I WOULD fix it - I'm a reputable developer, and I play by the rules.
I did receive 2 real-human emails back from Google in the process saying "thank you" and now months later my apps are all still online, so it appears I found the right problem.
I can certainly understand the frustration however. If there is literally nothing throwing up a red flag and you don't know what you have done wrong, and Google doesn't appear to give specifics, it can be scary.
The way I approached the problem was that Google probably didn't have a live human poking through my apps to find a violation, and it was most likely a "robot" that found the problem. This means it most likely had to come from a textual description or there was a potential IP situation. The email mentioned "spam", so I looked for the former first and found the over-use of the word "dice". Sure enough, that was it. Or at least I assume that was it, because my apps are still online now - months later.
That says really really bad things about the eco-system when your target 'developers' are so confused and unclear about what they can and cannot do, and the enforcement of same is not testable a-priori, that they have to resort to begging for understanding.
Either that or their algorithm really doesn't like you using the same word over and over again (this seems unlikely).
Spam apps are a real problem, and I personally won't be bothered by this as long as the devs that complain (and presumably trigger a human review in the process) don't have their apps inappropriately removed. So far, I haven't really seen any evidence of a widespread problem with inappropriate removals, just inappropriate warnings.