Obama obviously received a lot of unfair criticism from conservatives over the years, but one of the fairest criticisms was against his act of prostration before the Saudi king. By "fair criticism," of course, I mean that I agreed with it.
The entire US experiment is a repudiation of the idea of kingship and divine mandates for authoritarianism, not to mention the tyranny exemplified by that particular crown.
But I notice the same conservatives have little to say about Trump's kowtowing to the same crown, even as it butchers American residents and journalists.
I'm starting to think these people don't actually have any principles.
Obama's bow to the emperor of Japan could, I think, be defended as an attempt at cultural harmony. Because a bow means something different in that culture.
That bow to the Saudi king isn't some Saudi tradition, it's an artefact of monarchism itself. He's acting as a representative of the United States, and that bow was not deference to Saudi culture, it was an act of prostration before a person who claims God Almighty has placed him above all other humans. I don't think the US should accept that premise.
As for not meeting with them at all, I think that's a perfectly defensible view. But I think Obama could have still met with them, only making clear beforehand that he would not bow to the king.
Then it's up to the Saudis if they still want the meeting to happen. They need us a lot more than we need them.