Humbly very much in favor of your present policy, HuBob, always have been.
Agree with your two reasons, spammer ID and amusement, and add a third -- ridicule -- in other words, punishment. Sort of like a scarlet letter.
None of us likes to be ridiculed and punished -- we reserve that for those that truly deserve it, like spammers do.
Cheers,
Svejk