There wasn't even a need for "Homework Alert!" because
he even left the hint in one of the questions, hehe.
If he copied the question, then he'd just copy the answer.
For the question "About what do you object?", my reaction
is most similar to the fourth answer you gave.
(speculation follows)
perlmonks.org is a social system, and this is one
of its taboos. As such it performs the function of
supporting that system. Otherwise it might do something
like the AOL invasion of Usenet (probably will anyway).
Also certain people maintain/enhance their status by
denouncing the outsiders.