Mohammed bin Laden was illiterate. Besides Osama he had 56 other children, and 22 wives (he'd "divorce" them and assign them to subordinates in his company when he was bored with them). This happened btw to Osama and his mother.

Being illiterate, there was little he could do teach Osama or any of his other 56 kids on human capital. Mohammed bin Laden's only significant attributes were cronyism with the Saudi royal family and keeping accounts in his head.

An alternative explanation however, is that violent and tribal societies allow "big men" who are socially dominant to take more than one wife, and deprive others. You can see this often in cults such as Joseph Smith, the Branch Davidians, FLDS, etc.