Yess, I feel you about Kylie and Kendall not having that much of a strong relationship with the Jenner's, and I may be reaching, but I guess Kris had something to do with that, because Brody was in some episodes, I remember him in the one when he was taking care of Kylie and Kendall and the 'Girls Gone Wild' thing happened (Brody's friend fimling Kylie, which is creepy AF), and then an akward moment Kim and Brody had to, idk.
I mean, but at the end maybe they don't like each other that much; some families just don't get along with their parent's other family, even if it's theirs too, and some do, also, Kylie and Kendall grew, got famous and rich via the Kardashians, not the Jenners, so they could have just felt more comfortable with that side.
Alsoo, just remembered, I read somewhere that Kim begged Brody to help her get a cameo on The Hills and he said no.