I got to the bottom of her argument. Basically, it was soft science vs hard science. She doesn't fully buy it because social science isn't hard science. It wasn't anything more interesting than that haha.
Discussion
Idk why calling it a soft science is seen so negatively. Economics is a soft science but that doesn’t mean it isn’t infinitely valuable.
That's why I thought it was a weak argument, once I got to the bottom of it. Wah-men, I tell you....

GM brothers 🧐
But isn’t she right to insist on a higher standard for morals?
The theory sounds pretty democratic to me, just because leftist “liberals” believe it’s “fair” to take taxes and use force to steal and redistribute money- doesn’t mean it is a moral good to do so.
The elephant and rider can go and crush our houses if allowed to!
It wasn't that she was insisting on a higher moral standard. Her points was that social sciences are a 'soft" science and aren't fully concrete.
I don't think the theory is about what should be, but more about what is.
Whether liberals believe taxation is fair or not, while it may not be moral from a libertarian perspective, Moral Foundation theory simply observes that framework. It doesn't prescribe it as good or bad.
I think it would be more a political (objective) theory then? Maybe that’s what she meant by “soft science”
Morality is objective (Plato’s moral realism, Natural Law) imo 🤓