Ratings are ratings of a game's content. While most people don't care about the literal rating of a game, they do care about the content. Everything about a M rated game is gonna be different from a E rated game and the people who want to play them are gonna be different. Even the marketing is gonna be different.

I see you struggle with the word “most”.

And I don’t see how BOTW isn’t family friendly. At the very least, it’s in line with many Disney’s animated movies.

But it's not like the ratings correspond to what audience you want to target. It's just a recommendation, a warning for parents that some stuff might be too much for certain children. In today's age where a game like Rocket League can be a hit with adults, very few gamers care about ESRB ratings when buying a game for themselves. They play what they find cool and fun. Nintendo's problem in the Wii U days was that they didn't make themselves look cool. More than half their marketing for the Wii U involved 9 year old suzzie and bobby begging their parents to buy them a Wii U with games like an overly sterile and colorful 3D Mario game. That's not what older audiences find fun or attractive. Compare that to the Switch where you have kids, teens, and young adults shown playing games like an epic open world Zelda game, a stylish and flashy Arena fighter, a rebellious ink shooter, and a risk-taking Mario with New Donk City and Cappy possession. Switch era Nintendo is cool because their games and marketing are cool. Nothing aesthetically feels lame or sanitized. Nintendo's re-invented themselves as a company who can take risks, while still maintaining a friendly face. 

What adult or mature content it does not have?

For it to be mature, does a game really need to have realistic graphics?For a game to be adult oriented, does it needs to have blood and gore?Thats the whole problem.More and more the industry has been proving that these concepts are wrong on a fundemantal level.Overwatch, Fortnite and many more are proving that a game that utilizes a cartoony artstyle and "goofy" combat with nothing resembling gore or "hardcore" violence can appeal to a grown-up audience, to adults.

BOTW is a big, complex game with alot of freedom that managed to win everyone over, specially adults.Just a quick glance at the numbers will prove that, specially since this was a launch game, and we have data of how old were the people that bought the Switch at launch.A game appeal, kiddy, adult, or "wide", is mostly determined nowadays by how complex or "easy to approach" it is.And lets face it, BOTW with its huge world and myriad ways to play it isnt exactly kid-friendly.

Plus, isnt this topic a bit useless?First of all, most games that Nintendo released on the 9th gen have wide appeal.Can you really say that Splatoon 2 is really all that kid-oriented?Cant you just say that it is "safe" for everyone?Same question for Mario Oddyssey.Even Labo.Its not every kid that will manage to build those cardboxes.Especially the more complex ones.These games are not aimed at kids, rather they are friendly to everyone.You can even say that these games I just mentioned (barring Mario) are mostly aimed at teenagers, not kids, given their marketing and ads.

Well, didnt know that you could define as most when more than 40% of the games you mentioned dosent fall in the criteria you put them in.

And BOTW is family friendly.Or rather, it is for everyone.But you know thats not the word you used.

I used “family friendly” and didn't mention any games. 

Also, Bayo 1-2 are not first party games. 

What are you reading?

You come across as overly defensive. -__-

 Kids can't buy certain rated games, correct? Why are you saying it's just a recommendation then? It's against store policies. It's a rating of the content in a game. Again, adults won't buy a M rated game because of the rating but because of the kind of content they tend to have. It's the same reason why adults watch higher rated content versus kids' shows. Nintendo is doing what they've always done with their games.

M rated games are a special case as they're usually the more controversial of the ratings. Of course, there is content that kids shouldn't be seeing until old enough. My point is that Adults, or older gamers in general aren't not going to buy a game just because of what letter is on the box. 

It will always remain a stigma as long as Nintendo keeps trying to appeal to that E for Everyone.

Don't really mind that attitude to be fair, since usually the lower rated stuff tends to be also mature and dark, some even more so than M rated titles, games like Kirby, Zelda or Super Paper Mario. And as an example from another company, Klonoa.

It would feel as if Link was actually swinging a sword and damaging something. I'd find that meaningful.