And as a job they need to expect to follow the rules like everyone else. Entertainment around film and music has existed for years, but there they required permission to use the material. Videogames are no different. Heck, just showing a music cover requires permission if you want to show it, separate from permission to play it.
The rules are the most antiquated part! That's where the headache is coming from! The rest of the world is changing and Nintendo's digging their heels in to the old ways.
The copyright laws in question here were designed for big TV and film production studios for wide-scale professional broadcasts, where the notion of paying royalties was an understood part of the industry. They're worth millions, I'm worth millions, so money changes hands as part of the licensing process.
I'm going to dig up another tangential comparison here that will probably fly over some heads, but it's like Adobe and Photoshop. Photoshop is a professional tool, and was priced accordingly. But because of that, it was also one of the most pirated pieces of software, because every art student in the world realized how powerful it was, and it became this secret industry standard where probably something like 80% of its userbase didn't actually pay for it.
Adobe saw this powerful professional tool that they had priced for powerful professional people and realized they had a burgeoning market of lower-end users who could not afford the thousands of dollars they were charging for Photoshop. So they released a cut down version of Photoshop, called Photoshop Elements, for $100. That was still too much. People were still more willing to pirate the "real" version of Photoshop.
So now Adobe has moved to a subscription model. $9.99 a month and you get Photoshop. It stays affordable while also still technically costing a minimum of $120 a year -- just in smaller increments. They changed their policy to better fit who was really using their software.
Copyright law is still designed for powerful professionals and it is colliding hard and fast with users that are too small time to deal with it. Youtube won't even give you the time of day on these kinds of matters unless you're speaking through an acredited lawyer.
The "rules" are out of date, and at this point, only the shrewd (like Nintendo) are still sticking to them. This is a battle many Youtube creators already fought a year or two ago, and most other companies got the message and backed off. (re:
Sega vs. Shining Force)
Nintendo would rather be Nintendo.