So with a bigger budget, it would have been lizards, and then it wouldn't have been racist.
Well, however they appeared, the culture was still written according to various stereotypes of nonwhite cultures. It was largely Orientalist, as I said, but there was also an analogy made to the Native American custom of counting coup. So they were pretty much written as a generic Other. I'm not sure if a stereotypical portrayal of everyone
non-Western is much better than a stereotype of one specific ethnic group.
Are we so far to call every stereotypical portrayal of a culture racist?
Every alien culture seen in Trek is a stereotype of sorts, simply because nothing else is possible within the narrow confines of a TV episode. Klingons are warriors with a strong honor codex, with exceptions. Romulans are spies and traitors, with exceptions. Ferengi are capitalists, with exceptions. Bajorans are fundamentally religious, with exceptions. So essentially, all those cultures are caricatures with ONE specific trait.
You can interpret racial and ethnical stereotypes into any of these fictional cultures if you want. TNG Klingons seem to be modelled after the Japanese samurai. TOS Klingons and Romulans after the Soviets. Ferengi are Jews. Bajorans are Jews as well, and also (ironically) Palestinian. Cardassians are Nazis. And so forth.