while i think robyn has been a factor in the issues with the extended family i always feel too much blame has been put on her-
the pre-existing family had major issues prior to her inclusion which were so bad at one point that janelle and her kids left,
the pre-existing family had been uprooted and moved many times for years over the objections of one or more of the wives,
when robyn entered the picture the existing older kids were entering what i think most parents will agree can be some of the challenging parenting (and as a result-coupling) years.
add all of these factors together, mix in kody's paranoia and the great exodus to vegas and yeah-he's going to default to the wife who is still buying into the big, happy, mutualy supporting 'super family' with the priest head being kody. kody was still trying to believe this was their standing despite them living for endless time in separate residences across vegas, then in the houses that while next door to each other were in no way mutual homes.
i think that what has brought all of this to a head so dramaticaly now is-
the majority of the kids are adults, parenting adults is vastly different than parenting little kids. kody neither acknowledges nor respects his adult children's autonomy in making their own decisions (he demands to be the leader of all with no questioning). the kids are questioning and coming to their own conclusions which does not mesh with kody's,
when janelle left years ago it was physically, she did not take any assetts or income with her-she continued to pool money with the remainder of the family so he still had a tether of control. when christine left she (rightfully) demanded her assetts and walked-he has no control over her what so ever. kody is a control freak and to not have control over esp. the woman he has publicly said/written that he feels he did a favor to by marrying has to be driving him bat s--- nuts. that she is living so publicly happy, that 'her' children as well as janelle's are supportive and celebrating of her independance is likely a huge betrayal in his mind.
i think robyn bought into what tlc bought into when the show was pitched-one big happy family co-habitating together, 'love should be multiplied not divided'. i think she has said the same things to kody that all the rest said over the years about settling down and staying in one place (granted-it was where her oldest wanted to go to college), taking a more active part in their younger kid's lives...it's that he has bought into it with her to the exclusion of the remainder of his wives and children (i believe the pandemic compounded it and allowed allot of festering issues to come to the surface and finaly be addressed-issues that predated robyn entirely).