The unironic reason for this is that Zoomers have been largely raised by single mothers. Children are biologically coded to see their mother purely as a caregiver/nurturer and their father as the authority figure, but single mothers have to be both. On top of being both however, single mothers are also incapable of handling the stress that comes with being both, and so they end up being emotionally distant and quick to anger with their children, and instead of providing constant love/affection to their kid they give it only sporadically.
The developing boy's mind comes to deeply crave this tender affection, but because it is hidden behind a rough, mean, dominating exterior most of the time they associate that with the tender affection, which conflates into the "MommyDom" fetish we see today.