Thinner means more luggable, but if it restricts a workhorse machine from having more than the 16gb of ram the base model can also have because they can't fit enough battery to power it, then why not go all the way and shrink it to the size of the 12" MacBook? Well, because of the other components you might say! But, if the CPU throttles, the GPU throttles, the keyboard stops working and the anti-reflective coating peels off, all because of the thermal stress the machine is under when used as a workhorse, then is not much of a workhorse is it? Besides, no one is asking for an aircraft carrier, the thickness of the 2015 version was good enough for nearly everybody, specially when you do have laptops like the MacBook that do make those compromises.
Apple is sort of a luxury brand but the problem is they want it both ways. They want to be seen as an aspirational brand and as a workhorse brand. That is why they keep releasing FinalCut, Logic, and XCode. At some point those two ambitions are going to collide; most people think they already did.
No one is asking for a tank, you are presenting a false dichotomy as no one is confusing professional with ruggedized. Every serious complain about the MacBook Pro is about specs, ports and reliability, not unbreakability. In fact, based on your previous point about luxury machines I say you are the one that is confused. Are MacBook Pros professional machines or not? If they are luxury items as you claim then by all means don't make them waterproof but if they want to aim it at people editing 8K video on-site in Africa, which happens by the way, then ffs make the screen less reflective.