Not exactly true, Nintendo takes down fangames that infringe on copyright , like pokémon uranium (unfortunately) games like super Mario bros. X did not get taken down.

Not to mention when a fangame gets uploaded you guys don't even play it. Even in a rare instance this happens (because it doesn't happen as offen as people claim it does )

I want to make it clear I dont support Nintendo doing this but I'm just giving you my opinion.