Have you seen the UI? Nothing fit for adults, who value their attention and time.

Sorry, I don't see it. I can quickly jump around channels and server with shortcuts, the UI looks similar to other chat apps. Auto-Embed can be disabled, if that steals your attention. Or what do you mean?

They just don't like the design and are choosing a condescending way of framing it.

Because it's a video game accesory.

They market to kids, and have kid safety features.

I don't use discord in combination with games at all. But you can use it that way. That does not mean it's only for kids.

I mean the logo is a game controller.

If your company uses discord as a tool to communicate, it gives the message that it's like a game to you, that it is not serious, that you are relaxed,etc..

Certainly not the right register for serious stuff like an IT company, tax company, weapons, etc...

And it's not just semantics, the app was built for gaming, it has features and design choices built for that, one of them being kid safety. Not a corporate tool like slack.

If you are into that great, but it's what it is.

Yeah, it was build of gamers. I would also not use it for communication in a tax company.

That does not mean it's for kids only.