I had a stick burner and seasoned it for two reasons.
1)Its a hi carbon, lo nickle steel. It'll rust. The oil helps protect it. That's why I never cleaned the sides or top of the inside of the pitt. Only used enough water to get the grease out of the bottom. I only cleaned the grates just before a cook. Cooked on it for six years. Stored it in my garage and there was no rust on it when I sold it.
2)The initial oil helps the smoke kling to the walls. It takes many cooks to get a good kreosote build-up. This helps give the BBQ the unique "Pitt" flavor that everyoune looks for.
You don't need to use oil to season a stainless stee pitt, 'cause it won't rust.
Que on!