They really aren't. Alignment was never meant to be a viable philosophical framework.
I certainly don't mean to declare them as anything of the kind.
But I don't think it can really be argued that the alignments don't contain bundles of value-judgments. It's just that--well, they're rather arbitrary bundles thereof. They sound superficially nice to the ear, but become incredibly fraught if you take more than a moment to consider them. Hence why, as I said in part of the post you clipped, these things lead to difficult questions, because "Law" isn't one singular belief, it's a set of beliefs, and a person might hold a subset of beliefs from both Lawful and Chaotic, or from both Good and Evil, or whatever.
I mean, just look at the description of Good vs Evil from the d20srd:
Good characters and creatures protect innocent life. Evil characters and creatures debase or destroy innocent life, whether for fun or profit.
"Good" implies altruism, respect for life, and a concern for the dignity of sentient beings. Good characters make personal sacrifices to help others.
"Evil" implies hurting, oppressing, and killing others. Some evil creatures simply have no compassion for others and kill without qualms if doing so is convenient. Others actively pursue evil, killing for sport or out of duty to some evil deity or master.
People who are neutral with respect to good and evil have compunctions against killing the innocent but lack the commitment to make sacrifices to protect or help others. Neutral people are committed to others by personal relationships.
These are values-statements. "Altruism," "respect for life," "the dignity of sentient beings," all values, as is a willingness to "make personal sacrifices to help others." Having "no compassion" is another statement about the values a particular being expresses.
That's what I'm getting at. We can consider, at a societal level, whether a culture does things like (to skip down to
the L/C section), things like "respect[ing] authority" and "judg[ing] those who fall short of their duties." I freely recognize that it is possible to, frex, have a culture where it is normal to "judge those who fall short of their duties" while also being normal to "resent being told what to do," because those are distinct values within each bundle, revealing the rather weak foundations upon which D&D alignment is traditionally built. I still think it is meaningful to ask questions about what a society or culture places importance on. Just as we can talk about us Unitedstatesians being "prudish" or "hard-working" or whatever one might like to discuss, we can talk about whether the values or promoted virtues/vices of a particular D&D society lean it toward the bundle-of-values-called-Law, the bundle-of-values-called-Chaos, neither, or (as noted) perhaps both in different ways.