“Hey guys, I have a GREAT idea.
What if we impose arbitrary requirements on usernames but don’t tell users what those requirements are?”
<gets promoted, probably>

Some numbnut decided enforcing a language change is best for the user.
In India.

Bot protection: 0
Annoy humans: 1
Tick a box on the security checklist: 1

we need a special charater for max security.
no, not that symbol.
hmm hmm, not that one either.
bzzzt, try again.