I think its just Google protecting themselves legally.
Protection is good, but dictatorship is not good, gosh if I program into the license of a software I make, that when you delete it that before you can delete it, a box comes up and you have to click it before the software leaves your system, I have committed dictatorship. I think? It really sounds like a one way law. Are you sure Google does this? I mean it would be all over the internet.
Maybe you mis-read it or something?
Ah, well... I think Google just wants to know if you know what you did (and cleaned it up). There are enough legitimate reasons to NOT know why Google penalized you, in which case you can just select some of the options and write up everything you know (which could be "I don't know if I am banned or not, and don't know why I would be banned. Please check and let me know.).