What gets you in trouble is the way the regulation is written. A bus stop parking ticket is a NO STANDING violation. This means you can stop, drop-off or pick-up a passenger, and go. There are two (2) words in the parking rule that are poison to the drivers, “Temporarily,” and; “Expeditiously”. You can “stand temporarily” in a bus stop zone. “Lasting for only a limited period which is not defined. And just to point out NO STANDING zone, you cannot unload your property to the curb.
The problem comes down to fighting the ticket, the issuing agent will say they observed you for a time that was not expeditiously or temporary and most times they will side with the person issuing the summons. It is hard to prove even with sworn affidavits from passengers if you can get one so drivers avoid picking or dropping off in bus stops
So yes it is legal to pick up or drop off in a bus stop but it is not worth the time to fight the ticket so drivers don't.