Android isn't quite as bad as Windows, although I assume it can still be nasty. That said, if Android turned out to be the most anti-user system out there, that doesn't excuse Windows' sins.
If by "nasty" you mean malware, than I'll have to disagree with you. The closest thing I've seen would be rooting tools for Android, which, while benign and beneficial, wouldn't be necessary if the industry would stop locking our phones/tablets in the first place.
On the other hand, if you want to know the definition of malware, see the license agreement for any Microsoft program that has the phrase "Genuine" in the title. The agreement will likely mention each characteristic commonly found in malware, and force you to accept all of them in order to run that program.