For me fun is if physics are very basic, and the realism part is cut down to a minimum. Also i played way more hours in creative building ships and bases than i spend in survival, so i can clearly say ship building is a huge fun part of the game for me. My opinion isn't better than yours, but neither is yours compared to mine. The flaw you might see, isn't a flaw in other peoples eyes (in this case mine). The conveyor part in Space engineers made building nice looking ships way more complicated, or they where lacking basic features. It is more fiddling around with a flawed game mechanic than actual fun. So i actually hope those "realism" and engineering things stay out of the game or at least be a switch/toggle in the games options to turn off. And looking at a lot of examples... i am not sure if it is worth the amount of effort to create those realistic mechanics, if it only attracts a very small group of players. But looking at the way you descripe what ship creation means to you, i wonder if it is the right game you picked.