The Olsens aren't doing this after all, they have better things to do.
Idk, that was their reason without saying those exact words.
They do run a fashion company, but I don't think that's really getting in the way. Ashley supposedly is battling an illness, so maybe MK doesn't want to do it without her. I don't think they'd do it either way though, they both come off as if they are too good for such things now.