In fairness all of us respond to things on a visual level. The trick is being able to assess something fairly and be able to look beyond perceived shortcomings.
I don't think you can fairly assess TOS without appreciating the context of when it was made. Yes, it's not as polished and detailed as today, but that doesn't mean that's how it was perceived then and that it was deliberately substandard.
This is a mistake I think a lot of folks make, and largely unintentionally. I can look at the 1933 King Kong
and make many of the same comments. But when I appreciate what they were able to do with what they had at the time then I immediately see it in a wholly different light.