I don't have to say it with a straight face because your sibling poster did it for me. Something can be both common and stigmatized. Yes, divorce can be messy, expensive, emotionally fraught, and take time. Mine was, and it still wasn't 'bad' or even undesirable. Starting a business, learning an instrument, training for a sport can also be all those things. We don't call them 'bad', or 'evil', because we don't assume the end result is undesirable.

The comparison can't be to an imaginary world where everyone always picks the best partner. It has to be to the real world where people don't always pick the best partner and the absence of divorce means they're stuck with them.