Given Eggman is the most consistent adult he interacts with, can’t really blame him.

Having worked with the general public for most of the past 26 years, I can definitely say that "Act like an adult" doesn't carry the weight it should. Most adults aren't overtly dickish or otherwise exhibit typical "Karen" behavior, but they still passively do rude and sometimes dangerous things. They leave their trash wherever and don't put stuff back where they found it. Most of the people who are just constantly glued to their phones in public are middle aged adults, odd considering the common Boomer complaints about kids and smartphones. Too many grown-ass people simply have a complete and total lack of consideration for others. And that's just in stores. Out on the road, too many of them drive like idiots and generally treat an automobile as a toy instead of the dangerous machine it is.

And that's just dealing with people directly in real life. There's a lot of adults online that think it's perfectly acceptable to troll, stalk*, harass, demean, and even dehumanize other people, sometimes out of hate, sometimes for shits & giggles, but always for malicious reasons. It's amazing how much worse people get when they can hide behind a veil of anonymity.

I guess instead of "Act like an adult" it should be, "Don't act like an asshole."

*Looking at you, whoever keeps downvoting everything I post.