Sorry, but your phrasing isn't neutral or constructive. In my experience, if you're genuinely trying to be helpful, you'll be more successful if you try to be neutral and constructive in your language.
That said, I do want to understand where you're coming from. I do think that if someone's not confident they can keep their bike upright while sitting on it, not having it in neutral, having the engine off, having the side stand flipped down, and having both feet flat on the ground, they shouldn't be riding. I also have trouble picturing a gas station where a gas spillage would be a real hazard- I don't think that'd be up to code over here. Can you explain your reasoning? If I understand, I'll reevaluate my stance (no pun intended).