I totally disagree with that. As the patrons of the park who see it the most often through the eyes of a non-employee we do have a certain pseudo-responsibility to be critical of the park.
Employees know the reason why a piece of theming does work... whether there's no budget, or it's physically difficult to fix it, or whatever, but the patrons who aren't employees that go to the park regularly simply see that something doesn't work, or something looks trashy, or of an employee was rude, etc. That is the same perspective that a family of four would have.
That patronage rules the park, so if you do see something wrong, by all means, let them know. If you really consider yourself a PKI fan, then just letting something slide really is a sort of disservice to the park.
Regards,
Ryan