Not sure why people are so hung up on the terms "hilariously bad":
Because they're not for the most part.
And I meant the hilarious part. I loved many of those fights, they work brilliantly as a piece of comedy.
This one needs a "weeeee" dubbed in, but is pretty hilarious on its own.
Well, it's nice you found them funny, but this is one I have a lot of respect for because Shatner did all of it himself rather than resort to an obvious stunt double. It's a lighthearted episode and this scene was not meant to be taken seriously (Hint: the music).
60's TV fights were made to be theatrical and entertaining, not realistic. And they still pack more energy and power than some of the later Trek brawls.
Only some of them have aged poorly, and I would say Kirk's slow mo vs the Gorn would be one I understand being chuckle worthy. But mostly, nope.