Probably because they think they're such superior detectors of satire that they will never themselves be hookwinked, and then Just-World-Fallacy away anyone who is.
While also, of course, bragging about all the places they got into by carrying a clipboard, and what an extreme injustice it is every time someone is falsely identified as an intruder.
https://fox8.com/wp-content/uploads/sites/12/2022/10/AD65F49...
It said the department was hiring, asked minorities not to apply, and said that passing a hearing test and a short multiple choice vocabulary test guaranteed employment.
https://fox8.com/wp-content/uploads/sites/12/2016/03/3.png?w...
That seems pretty clearly parody to me.
Evidently a jury presented with the facts of the case disagrees with you since he was acquitted of all charges at trial.
Go ahead and find out yourself: make a 'parody' account of your local police office by using their logo, badge etc. and then some fun posts. Have people call 911 out of confusion. See what happens.
Honestly why does anyone think this is not wrong?
In a private context, you could probably sue, but we're talking about public emergency services here. He's literally impersonating a Police department, a wing of the Justice system.
If it was a totally clear 100% parody so that nobody would be confused, fine, but I don't get that gist.
Finally, even if it was theoretically legal, it's not like people aren't arrested for things and then let go because they were innocent. So long as the Judiciary has sufficient cause, well, people get arrested.
If this guy was truly impersonating the police force and it was not clear it was a satire, I think there was 'injustice' that he probably ought to have been slapped on the wrists and told to take it down ASAP. If it was an absolutely clear South Park parody well then maybe it's a bit more complicated.