it's a shibboleth. In the same way we stopped using Pepe the frog when it became associated with the far right, we may eschew em dashes when associated with compuslop

I never understood why so many people would yield their symbols and language that quickly and freely to others they dislike.

In other words, I really hope typographically correct dashes are not already 70% of the way through the hyperstitious slur cascade [1]!

[1] https://www.astralcodexten.com/p/give-up-seventy-percent-of-...

The alternative is… what? ‘Defending’ against the use of Em-dashes by LLMs? Or people reacting to that?

You might as well be sweeping a flood uphill.

Tilting at windmills at least has a chance you might actually damage a windmill enough to do something, even if the original goal was a complete delusion.