Provide the proof (examples) to support your contention, the North Hollywood incident is essentially a one-off incident, I have not found any evidence of armored vehicles being used in such a manner since that incident, don't mean that they were not. A Google search returns many results of these vehicles being used to protect cops...protecting the public, not a incident yet.Police dogs are routinely "used" improperly yet they remain in service (see the thread re the woman accidentally shot by a cop defending himself from a dog) almost without exception, your contention "it will be taken away" is without merit. If they won't take dogs out of service do you really believe that a inanimate object will be taken out of service.
Maintenance is not a red herring, some LEAs refused to take free "MRAPs" cuz they couldn't afford to keep them, even though they would be used very minimally. It is a valid point that mutual cooperation be a option. Smaller LEAs get the benefit of a larger LEAs resources.
I'm not sure why you think that I contend that LEAs have these vehicles to oppress the citizenry. I agreed, earlier, that I have no issue with LEAs having them. In times of civil unrest these vehicles are essential to provide cops the tools they need to manage civil unrest while attempting to respect rights and not violate the law. It is a no win situation for cops some times and cops, as well, are not to be held harmless in all cases.