Are relationships so fickle?

A friend of mine has two daughters and a son. He has educated them well, in that, the eldest daughter is a doctor, the younger one, an engineer and the son is doing his engineering. Both the daughters are married to IT professionals, who’re working in reputed firms and hail from good families. Then, where’s the problem, one might ask! And that’s my thought for the day.
Both the daughters, their husbands and their families are not on talking terms with this friend of mine and his wife. I’ve not pestered the real reasons from the hapless dad because I consider it as his very personal secret and it’s my firm belief that I’m only supposed to lend my shoulder for him to cry on, as and when required. The daughters have been married over a timespan of the past three years and both were arranged marriages. Having touched upon each of their family backgrounds, I really can’t fathom their ‘katti’ culture of the present!
What makes my friend quite sad is that, both his daughters, have not been able to take a stand that their parents have to be treated, in all fairness, well by their spouses and their parents.
Does a girl willingly surrender her identity completely, only to be accepted in her husband’s household? And that too when the protagonists are all well educated or should I say, are sufficiently literate but not educated? In this case, the latter seems to be more appropriate. And the son gets whatever he asks for, the parents are so indulgent.
Apologies for being harsh, but my random thoughts, as usual!