What is the pragmatic difference of using the rule vs. not using the rule? I don't see one.
The forum is broken either way, so no difference to you nor me really. Until theymos is replaced, you can ignore most rules and dance around like CH & trolls do. I have nothing against your suggestion, other than the increasing visibility of forum staff mostly being worthless.
single user could handle whole campaigns that way.

Interesting, but why could this not happen
right now?
Because an army of imbeciles would attack the user once found out. Even if this rule were to be dropped, in special cases (e.g. me) you'd have an infinite number of threads and posts bashing the user.