A lot of the premises of TOS are good ones, but the special effects aren't so good (budget and technology, understood), the acting is often over the top, and a lot of the details are maddeningly inconsistent.
As we get further and further from the 60s, people lose sight of the context of TV and film productions of that time, and they just write TOS off as "cheesy" and "cheap."
The TOS special effects may look primitive to us today, being accustomed to hyper-realism half a century later, but TOS was by
no means a cheap, low-budget show.
TOS was actually one of the most, if not
THE most, expensive network television shows of its day due to the constant need for visual effects, not to mention sets and costuming. The average cost per episode was $185,000, which is about
$1.3 million in today's money. The pilot episode "The Cage" alone cost $615,751 to produce. Adjusted for inflation, that's about $4.6 million.
And for a television production of that time, the visuals were
groundbreaking. Seriously, try to think of another show of the mid to late 60s that matches the quantity and quality of TOS visuals. Most shows on television at that time needed maybe one visual effect once per season, but TOS had to have four special effects companies on rotation due to the constant need for effects shots.
Also, acting at that time was
expected to be more grand, theatrical, and bombastic. Ever seen anything with Charleton Heston in it? This is a long tradition inherited from stage productions.
Kor