It's cos of the sweary boatmen, C.
In the late C18th, they built some pleasure gardens at Vauxhall. {cf Vanity Fair.} It had a bandstand, booze-wallahs and "Turkish food emporia" which I guess is how your late Georgian toffs referred to kebabs.
But it went bust cos the ladies didn't like the uncouth language of the boatmen and stopped going there for nights out.
Thus they had to invent the bridge. Music, booze and a kebab, followed by a journey home in a vehicle controlled by a Londoner with a poorer command of English than oneself. How times change.