A lot of folks tend to confuse "appropriate for kids" with "made specifically for kids".

Games like Mario, Splatoon, Pokémon, etc are certainly made to be kid-friendly, but that doesn't mean they're not just as appealing to adults. The E rating stands for "Everyone", not "Everyone under 18". 

I am super late to this thread but I calculated the surface area of the bars in the bar chart for each age group to give somewhat of an estimation of the exact percentages of age groups playing on the Switch. Here's how it looks:

Based on this estimation, around 40% of Switch players are 18-29 years old, and only 18% are under 18.

I have a feeling a lot of 18-29-year-olds playing the Switch were introduced to Nintendo through the Wii era and came back during the Switch era.

IMO this demographic range does not surprise me at all, it's common to see many adults play the Switch for multiplayer experiences and to play as a more casual system on the go.

I'm also late to the party, but I wonder in what way they got the data? If this is from things like a Nintendo account, then I know most people lie about their age when they create an account so I don't think it's entirely accurate. Kids can also play on their parent's account, and most kids put their age above 18+ to avoid age restriction and such.

It is an interesting thing to think about, but it doesn't really tell us much beyond normal demographics. For example, in the countries that the Switch is most popular, the population tends to be older. Thus, the average owner of the Switch will be older.

Now of course we have to account for generations that don't really game, IE: since before gaming existed for the most part. But other than that owners of the Switch pretty much reflect population demographics.

And then their is the generation that can't really spend money, the super young kids. They can't really choose what to buy, and even if someone bought it for them, they probably inputted their own name.

Damn I’m old as far as Nintendo fans go. I feel like I’m near ready for carousel :(