@dwmatiz Also I could expand on what I meant: Only programmers would have anything against the specific '!' character as opposed to others, as that's the only area (I know) it has semantic meaning when prepended to a word. ¡Not even Spain uses it!
And if there's no specific preference against for most people, then reasonably there's no reason to choose one character over the other. By following the rationale of how the #hashtag was chosen by normal people because noone ever uses # at all, but we're sort of out of characters normies don't use _and_ can be written on a majority of keyboards easily (~ is not easily written, to tie back into that suggestion).
cc: @clacke