Yes, it is, ESPECIALLY in the US, which enforces IP protection more than other countries.
IP law is very complicated in the US, extremely complicated. I'm not even qualified to really comment on it. However I can tell I actually understand it a lot better than you. You be assuming things bro, doesn't work that way.
Using an IP for commercial purposes does not qualify as fair use.
An example of where you're absolutely wrong and would know that if you spent 10 seconds thinking it over. There's a lot of case law addressing this even on Wikipedia, by all means, read it.
Why do you think racing games need to license cars?
Because of trademarks, not copyright, calling it "IP" makes it confusing because they're entirely different things with different rules.
Ok, if it's not a legal issue why did Google accept Nintendo's copyright claims?
Duh, because it's obviously easier to not give a shit and just do it. Seriously, you must be aware of the 10s of 1000s of erroneous DMCA requests that were nevertheless honored.
Eh you know what, you're normally very thoughtful, you appear to be disinclined to do so here despite a wealth of good information being out there for you. Believe whatever you want, fuck it.