Another likely contributor is some states require all party consent on audio recording, which may make video inadmissible as evidence. And the homeowner is committing a felony for each instance of an audio recording without consent. If a camera breaks up a recording into separate files, each file is considered a separate felony.
So rather than wading through all the laws in each and every jurisdiction, and potentially getting a homeowner in hot water, they simply revoked law enforcement access.
While I am not a lawyer, live unrecorded audio in a camera feed or doorbell camera might be treated differently. Would be no different than talking to someone on a phone or intercom. One could also argue a visitor pressing the doorbell camera button could be considered implied consent.
Florida is one of those all party consent states, so I disable audio recording on all my cameras.