Wow, for once Tiali is actually close to the real answer!
Pretty much, because the distances between adjacent systems would require month long cross-terrain times or so. That and its a game balance thing as well. Was brought up as an alternative fix for Interdictor covered systems and escaping.
I calculated the approximate distance between system squares in SWC before, and if we used any number close to a realistic representation of the size of the galaxy you'd be traveling for at least a year to get from one square to the next.
'Calculations' and supporting canon evidence aside, the question is: should ships without hyper be able to escape a system?
It would be nice to be able to travel square by square without hyper at reasonable time delays, some 12h to 72hrs, as long as the delay keeps said escaping ships visible in the system until the delay is done (not dissapear when initiated), and said ships appear with a directional arrow so other ships can follow it that seems like a better system than what we have now.
It wont be considered because its 'complicated', not because of realism, because its actually unreal that you cant escape the system only because that space between systems is not coded.