So? People like that already existed long before COD, Madden, FIFA, or GTA. There are or were plenty of people I met in life who bought games off popularity and nothing else. Sonic, Mario, Golden Eye, Street Fighter, Mortal Kombat, NFL Blitz, Resident Evil, etc. I can go all day. Your definition does not change the fact, many people have used normies just to shut out and look down upon others to feel special, or took offense to anyone outside of their special little club, or doesn't look like nor act like them.
No, that would just be a shallow asshole and philistine who doesn't hold value in art to any copacity or looks down upon it.
Most people don't find gaming weird, or are adults themselves. The ones who look down upon gaming nowadays are mostly old men and women, who viewed the genre with contempt or chose not to open up their world view. Being interested or not in nerd culture doesn't make a person inherently better than the other. That applies to me too.
I've dealt with my share assholes, but using normies while less harsh by the ever minuscule comparison, really does not say much and is still a form of looking down on someone for not being X or not interested in X. Nothing more than an unnecessary division, but with a grudge, built up resentment or using on others who weren't even born at the time, or have different interests.
I was never called a manchild, but I remember a few butt fucks called me a slur against those who are gay/homosexual, just because I like Sonic and Viewtiful Joe. I was 17 at the time, but they got their asses handed to them by my older brother. I didn't need him to do that, but it shows my big bro and I always have to look out for each other. And those fools knew how to keep their mouths shut after that.