neither one actually built the Okomotive OR the Sailmarine. so they had no say in how they were made or their fuel consumption-ness.
also, okay, then go around them. maybe this isnt the game for you.

"You're so smart, you're stupid" seems to apply to the OP here :)

You seem not have noticed that in order to operate the vehicles that they do boob their heads against giant buttons, OP.

Games like other media of fiction too they always have a particular scope. This scope is very narrow. It is called "arcade" level of realism.

The protagonists also seem to be children. So this is like a real-time version of a children's book.

It is really, really, pointless to argue about realism in such games.

Protagonists are only as smart as the player, aren't they ?

That's game mechanics, not sign of their intellingence within the lore. It's a game and like many games it separates game mechanics and engine limitations and features from stuff, that's in the lore. And since it does, you should too. It's quite a common thing in games. People really should make difference between lore and how a game works. Then there would be less topics like this, that make you look kinda ... not the brightest, you know. Maybe you've employed this tactics to harness clown rewards, which seems to be a pretty common tactics here on Steam as well, but it won't prevent people from making an opinion about your intelligence. Like why are people doing this? What do they gain from intentionally looking stupid to earn Steam points? Do they matter that much to them? Even more, than what people think of them?
Well, anyway, there you have it, it's game mechanics, obstackles and puzzles to solve, instead of going around them.