playing within your means is not about mimicing real life.
Game mechanics have costs and rewards. Not all rewards are accessible at all costs. That's an expected and logical way games behave. The fact that real life also sometimes works that way is beside the point.
I have the impression that game mechanism here counts very little, not to say nothing.
I guess that the unkeep it's nothing more but an incentive to keep the player logged during the month, exactly as the arx given free (when soeone gives something to you, it's you that is the product: don't ever forget this...).
Keeping what Fd has worked in last period (Fleet Carrier interior) just to keep it behind an unkeep to me sound a so masochistic choiche that only Fd - if ever - knows the reason of it.
Having little time to spare (in solo mode) in play time (due to having a real life), after I have walked in my FC with almost all space closed (due to service suspended) I couldn't say to myself: great job Fd. Now keep it by yourself.
There are 3 bilion in my Fc but I am doubtfull i'll log again.