In principle I agree. But at some point there were many enough of them that anyone who gets involved with Musk has very little legitimate basis for claiming to believe there won't be others.

significantly less odds that she's going to halve your fortune on the way out if you're not married, so it would tilt investors/investments way less.

morally I don't really disagree with you, but practically I do.

It's not like they don't know the deal up front. They certainly aren't reluctant to be the next in line.

Is it worse or does it dilute the bad if there are a ton of baby mammas not just a "girlfriend who is also the mother of a couple of children"? I don't like the guy but it kind of feels like it somehow isn't as bad when it's just open, repeat behavior and nobody thinks he is even trying to be exclusively "with" these women. I have no idea what their shared understanding is but it might not be as bad as your framing makes it sound if that is openly known between them.

Not a lifestyle I could ever be proud of living personally but ymmv and elon seems to be enjoying himself.