Well, Han does claim to have flown from one side of the galaxy to the other. Which could be BS, of course, or it could be that the galaxy is actually tiny, or it could be that hyperdrive is indeed really fast.
Did he claim it in a manner that suggests it's an achievement? Because a quick day trip isn't an achievement!
Mostly, though, I think George Lucas just wanted a nice visual for the end of his film, and didn't really give much thought to the physics of it all.
That is most certainly the case. I agree entirely.