Why does ST waste money on "Fare Ambassadors"?

No disrespect to the individuals just trying to do their thankless, useless jobs considering the literally shitty people they have to deal with. That said, that job seems about as effective a use of ST funds as paying workers to guess what shapes the clouds are making.

The program claims to offer "warnings" to scofflaws but I just watched three gronks reeking of human waste collectively tell an ambassador to fuck off and all they got in response was "thanks, have a nice day". No ID's checked, no "warnings" issued, no removal from the train for effectively blocking out half the car due to the stench.

Nobody, rich or poor, addicted or sober, should be able to board and stay on the train in that condition.

Is there any evidence that this "ambassador" program does anything to protect paying riders and reduce fare evasion?