Yea... It was said many times... over and over again... They doesn't seems to do anything about it.
Normal ships shouldn't be able to fit 1ere class. Luxury passenger mission should appear a lot more often and pay a lot, so you could stack them and make Kruger's ships usefull.
Most ships should only be able to do economical and business class passenger mission, maybe with the exception Imperial Cutter as it has a rich looks.
Beluga Liner is the only ship with very restricted module slot. Maybe Military ships could have the same. This way Imperial Cutter would be a little less effective as a hauler.
And if they add more cargo vessels, people would use them for hauling instead of military ships... And SLF, wings, protection would then serve a purpose !