Gary could easily have made the ship blow up, or crash into the planet. He had to be stopped, period.
But if he could easily make the ship blow up or crash, how
could he be stopped? Hitting him with a fist would be the least likely way to succeed!
You know that. But Kirk didn't think of it. And more importantly, the writers and director didn't think of that.
And at the top of it all, there was a Fight Scene (I don't remember if Kirk's shirt got ripped in this episode...).
But by comparison, it was better than TNG would have done it. At the first sign of trouble, they
held a meeting. The first time Picard actually socked someone, I literally stood up in my living room and applauded.