I guess it's because a good chunk of games on Microsoft and Sony platforms are supposed to be realistic looking.
When something with a different style like Sunset Overdrive comes out, it looks radically different compared to something like The Last of Us for example.
We've grown up with Nintendo for so long, that we just associate the vibrant colors of games like Mario with kids I guess.
"Just for comparison Uncharted 4 was 20x bigger than Splatoon 2. This shows the huge difference between Sony's first-party games and Nintendo's first-party games."







