Why does Superman go back to beat up the guy in the diner?

I hear You brother and I totally agree. What a massive goof on a solid film. Why didn't they just remove it!?!

I'm glad someone else noticed this. I was really enjoying the new cut, but tacking this scene onto the end confused me so much that it took away from my enjoyment. I even re-watched the last couple of scenes with the director's commentary on to see if they commented on it. I noticed Donner referred to the previous scene (where Lois says Clark is "super" for going out to get her pizza) as the "final scene," but then when the diner scene comes on, neither of the guys mention anything unusual about it. After the insane amount of painstaking work so many people put into creating this version, I'm simply flabbergasted that not a soul caught this monumental contradiction.

It does seem a little weird. I wonder if also he just wanted to teach the guy a lesson so he won't even consider doing that in the future?

I have a different theory; imo, as evidenced by Lois having vague notions of "the North-Pole," saying that she feels like she's sitting on the biggest story of her career and then beginning to write a story entitled "Superman Takes the Day Off"the time-travel did NOT fully erase everyone's memory. Now, who's memory got fully erased and who's only partially, and how all that works, LOL; that's where suspension of disbelief comes in. But again, the scene with Lois, coupled with Clark being recognized in the diner indicate to me that the time-travel did not fully erase everyone's memory; (if you look at the last scene between Lois & Clark in the Daily Planet, Clark even seems to recognize this before he walks out the door).

The other problem with the scene is Clark is wearing an entirely different wardrobe than in the previous scene where he goes to pickup the pizza. And even then, he is going to pick up a pizza, but he stops at a diner where he doesn't even pick up a pizza. I doubt such a diner would even serve pizza. So, it comess of entirely as if he went there just to humiliate the jerk after stopping off for an unneeded change of clothes. Very sloppy work. They could've just cut the scene out, but Donner didn't seem to mind adhering to any continuity with this edit. Granted, he was restricted by what had been shot a quarter century before, but sometimes, you have to make critical decisions that maintain the integrity of the movie.

-NJM

superman got hurt, no matter how much time travel he did the fact remains that he still got hurt, even if he changed it from happening. He still remembers it and will want revenge for the pain he felt, so a good ass-whooping was in order

"sir, sir, i gotta check and see if you've soiled yourself, I'll get to you in a moment, sir!"

I thought that at first too, but remember the events of the bad guys coming to earth and lois and clark's romantic getaway are assumed to be happening around the same time but maybe not exactly the same time so just maybe he spun the earth around enough to stop right when he got his butt kicked but before the bad giys got out of their prison. I don't know. I think I am just making excuses because that scene made me very happy as a kid and would have bad sad it it was removed from this version that I thought ws very well done and I am glad was taken out of the box for us. I didn't love going to the "spin back in time" well to end both movies, especially since it was so awful to do it this first one, but Ill deal with it. Thought the "mind erasure" kiss was a better way to go, but it was the only thing I liked better in the original than the DOnner Cut.

the villain wont be in the Phantom Zone for long.
He turned back time, meaning they will be freed the same what they were in the first place. Nothing to suggest he went and re-directed that missile to miss.