Your post made me laugh, but that's true, stations seem to be more programming than personality today, go on and play the tunes.
Maybe stations are picking up on what mainstream press thinks a pirate station's format is, all music with no IDs heard, or any talking. The public will describe a station that way, 'all music, so I thought it was a pirate station.'
They must have a microphone, but never turn it on or take it away from the speaker that's playing their shows and actually talk into it.
On the other side, maybe ops think that going on the mike opens them up to personal ridicule, where if people don't like their music, it's the music's fault.