EDIT: Just did a sanity check search, Mario Kart 8 playthrough, been up for 2 years, a million and a half views: https://www.youtube.com/watch?v=BR0l84gjEXg
Last year Nintendo made a program where Youtubers could sign up to be Nintendo partners, and in return they could keep somewhere around ~70% of the video ad revenue, but they also had some weird clauses.
Most people who do Nintendo game content do so while knowing that they are not going to be able to make ad revenue off of it. That is very well and fine for people who do it as a hobby, but some others do Youtube content for a living, and it's nonviable for them.
I don't have a particularly strong opinion on the subject, just wanted to let you know that it _is_ a thing.