I do understand how annoying things like that are - I get them all the time from people who seem to think that they should report bugs in Some::Module to me because I list that module's pre-requisites on CPANdeps. Nevertheless, I try to be gentle. It doesn't cost me much to point them at the right RT or github tracker.
Reading the replies, I get the impression that my statement was showing reasons to be impolite. I never meant that: I meant to say that I would understand authors to get upset, annoyed and impolite when that happens. As all of you say, we should still be correct and polite.
Thanks for all additions. Even the regulars (on CPAN) can learn from this discussion.