I completely agree with this, and if folks want to design gear, the rules should be available as a supplement, and those who do not should have the choice not have be forced to use them. I also noticed the trend when it went from displacement tons to kiloliters. I don't need that much detail, I want a 200 ton free trader with "X" amount of cargo (in tons), "Y" Jump, and "Z" maneuver. Then a TL 14 laser pistol with "X" number of shots that does "Y"d6 of damage and holds "Z" shots.
I agree. Sadly, for many if not most games, gear lists are compiled before design rules, and making the latter match the former while retaining sufficient verisimilitude vis-a-vis real world gear/physics becomes an exercise in frustration.
The ideal, of course, is the creation and validation of the design rules before creation and publication of gear lists. Whether this is a practical expectation or not is another question entirely.