300 metres isn't much at all. And certainly not enough for what we saw on screen
It's over three times the length of a football field. It's longer than a Nimitz Class aircraft carrier. Ever been next to one of those things? They're fargin' huge. You just proved my point, you really DON'T know how big we're talking about here.. you don't really comprehend it.
(And using the screen as evidence is folly because the ship would clearly have three or four different shuttlebays with different sizes and layouts, depending on what shot you're looking at.)
Truth is, a lot of sci-fi television/movie fans have developed a SERIOUS case of penis envy. Everything always has to be bigger, bigger, bigger. That Star Destroyer not impressive enough, here's a SUPER Star Destroyer! Need to be more impressive than the TOS Enterprise? Here's one seventeen times the size!
Seriously, Spaceball One was created the way it was for a
reason.. and the desire for a mega-huge starship
Enterprise is exactly what Mel Brooks was poking fun of.