Genuine question: how does the lightspeed ram break star wars lore?

Maybe I am an idiot, but in the original Star Wars film Han literally says “Travel through hyperspace ain’t like dusting crops, kid. Without precise calculations we’d fly right through a star or bounce too close to a supernova and that would end your trip real quick, wouldn’t it?”

Colliding with things in hyperspace has been implied to happen since the beginning. So why is doing it on purpose suddenly lore-breaking?

I always thought it was cool, I just don’t understand the discourse.