Only with Youtube videos when it comes to monetization.

Anyway, they have a right to do that.
I presume they're doing that so that they can advertise their own products on gameplay videos.
If you say it's morally wrong to do it, let me just say that everyone has different ideas to what's morally right and what's morally wrong.
Like, the Free Software Federation believes that the right thing to do is to open source all of your products (and AFAIK, it's wrong to not do that).
A lot of the software pirates believe that it's morally right to pirate software. Most of the devs of said software, though, don't.
So, "what Nintendo's doing is morally wrong" is more of an belief than a confirmed fact.
Hey remember when you used moral relativity bullshit to defend a genocidal madman?
Just because people think that they're good, that doesn't make their crimes more forgivable. Also don't start on this whole 'he without sin' crap. Sure everyone has committed a 'sin' by some measure. However, that doesn't mean we can't make judgements. Nothing would ever get better if people reacted to evil with 'oh but i've also been sin'. Few people are saints, and we can't live our lives hope for one to come along and fix everything. Sure 'microtransactions in games' is hardly a subject of life and death, but treating every problem with doormat like apathy because you lack some 'moral purity' won't help change any issue, especially the big ones.
Companies have probably been screwing people over for money since the concepts were invented. That doesn't mean we should accept it.