I know most people don't mean to be thoughtless & uncaring for anyone else but that is the way many are. They have never driven a large vehicle so they have no clue of what the challenges, & how car drivers can make them easier, at gas stations are.
Diesel is often at the end islands, the easiest islands to get to. Gas is also available at these pumps so where do you think the thoughtless car driver goes? The car driver has the option of using any of the gas only islands. The diesel RVer or truck driver does not.
It gets interesting sometimes.