Now its the opposite..................
Actually, the fast food industry used to be part time work for mothers while the children were in school and teenagers working part time for job experience and spending cash.
That all changed in the eighties when the economy picked up, mothers could go back to staying at home and their coffee klatsches and teens were either given money by parents or were told by their peers that fast food was for losers and the only acceptable jobs were in retail like clothing stores or record/ video stores and the like.
That's when employers were forced to look at the only source left with useful numbers, the Hispanics. And once that happened it was inevitable that they took over, because they then made it so uncomfortable for non Spanish speakers of any other race that they just didn't apply.
I know this because I ran fast food in a well to do California city until 98' so I saw the change from the inside , so to speak.
That may be the case in California, but the rest of the country didn’t have massive amount of Hispanics/Latinos at the time.....................