Well they originated during TOS, and having them be Humanoid was the only way to make them convincing.
My philosophy is if you can’t make truly alien aliens, don’t include aliens in your story. The Trek universe is a largely anthropocentric universe anyway, so it would’ve been a better course of action to have made the Vulcans/Klingons/etc. derivations of humanity and left non-human entities out of the picture entirely.
or you could just decide to enjoy the show and not nitpick at how you wish in-universe explanations were this and not that.
Everyone in the galaxy speaking English doesn’t stop me from enjoying SG-1.
I mean, if you’re going to dismiss a common-ancestry explanation as junk science, I don’t see how saying that common ancestor came from Earth would make it any better.