Pride does not want police participation at their private event, that is their prerogative.  Would you want your historical abusers to walk side by side with you when they have never shown remorse, apologized or made any manner of conciliatory efforts regarding their historical treatment of gays?  Or blacks?

Have you spoken to any openly gay officers to find out how the have been treated by their fellow officers? To this day? How about female officers?

The police approach the community with an us vs. them attitude, so it's perfectly understandable that Pride would reflect the polices very own approach to the public.

This move by Pride should send a very clear message to police, that the police have though their very own voluntary actions, broken the social contract and the gay and black communities do not trust them to behave lawfully and respectfully with their public employer. 

Note to police, if you violate the constitution, you will be treated accordingly.