Saltily responding to another comment on this thread I think I know why I have such a visceral reaction to this sort of thing. It's not so much the infantilization, but infantilization as a culture. Think in analogies:

• Suit and tie =~ lobster suit pjs
• Binge drinking whiskey with your law firm =~ smash tourney after hours
• Tan =~ pasty and sunless
• Tasteful desk pendulum =~ legos
• Board room decorum =~ developers in pjs at a whiteboard
• Getting drunk on a yacht =~ getting drunk at an escape room

I don't agree with forced participation (explicit or not) in an of the above activities, but it's all still corporate culture. You don't do it you don't fit in. The combination of childish activities with forced participation in them is what makes it terrible.

Something in a gray area: video games. Some people think it's childish, some do not. I personally do not. I 100% do not view being a 'gamer' as developer cred and making smash tourney a part of the culture - even doing them as a team event because it is exclusionary to the people that don't enjoy it but might feel compelled to do it for team culture reasons.