There is no evidence that the guys were laughing at her or just letting her lie there. That's an assumption. To the contrary, there ARE pics of them helping her into the car. These kids seem to get the shaft at every turn.
What about the "thank your grandpa for my cotton shirt" remark? These guys have no class. White, privileged? Maybe. But apparently their privileged upbringing didn't include class.
And remember, she arrived at the party visibly bruised (probably badly if noticeable on black skin,) and drunken. Not ONE of the many guys turned her away (or helped her,) at that point. This whole freakin' mess could have been averted if someone had stepped up to the plate.
Hell, they needed Uncle Buck* there to turn her away...just as he did the entertainment clown that arrived drunken for his nephew's Birthday party in the movie. Big dumb Buck even knew better.
*Obscure John Hughes Film referrence.