They are not your friends; it is not a generational thing or anything else; it is a personal space thing.

I would tell your daughters they are not allowed to bring anyone else over to the house, they may come do their laundry, etc. but you do not need other adult strangers in your house; it's not play time and you are not holding a play date for the friends of your children!

They need to grow up and take responsibility for their lives (you did, so they can!). The fact that your daughter did not rein in her friends, the "tried" part is lame, means she is unable or unwilling at this time to act the adult in your household so she does not get adult privileges in your household.