What I recall hearing more often is that a city doesn’t want to pay extra for the ammunition for the .45, and some “smaller officers” don’t think they can handle the recoil, which would mean more extensive and expensive training for them.
Why does anyone believe this must be an “either or” kind of thing? If I was a cop I would have no problem purchasing my own weapon and ammo. If I want to carry .357 or .45 it shouldn’t be anyone else’s concern, frankly.
The problem with hide bound government bureaucracy, if one person shits their pants, they make everyone wear diapers. That’s just stupid.