They would never have done this if the women involved were overweight / middle aged etc.
And yet, butch lesbians also get assaulted.
This is a classic case of sexual assault primarily then a homophobic crime (which is a lesser crime with lesser penalties) - if they hadn’t been on a bus, maybe walking down a dark street, the boys would probably have tried to rape them after the beating.
No, this is lesbophobia fuelled by "lesbian" porn which fetishises women's sexuality for the titillation of men. I do agree that corrective rape is a thing, but that happens to butch as well as femme lesbians.
This type of thing happens a lot in London to attractive gay women.
It happens to lesbians of all shapes and sizes all over the world.