It looked to me like he left to get *away* from people.

The middle of the ocean isn't exactly the place to go to live a life of saving people. He was there when an emergency happened, and made a snap decision to help because he could. He was trying to *hide* from people.

Do you think working at that Diner was due to his need to help people? No, it's a low key job. He saw all he could stands till he couldn't stands no more, and stepped in when Jethro was getting to grabby.

He didn't go there with the intent to help. Thing is, no matter where you go, you'll find someone in need in some capacity.

Further, the moment itself is not petty but it's not exactly necessary to tell the story. It's minor. His father was his guide and mentor. He was gone. Clark was now a man. He let his father die because he trusted him. if you don't think that kind of loss would spur a man to leave home and set out to find himself in the world, I don't know what to tell you except that you're probably a little too determined to find fault where there really is none.