Musk hasn't to my knowledge financed any architectural design projects for a long-term livable Mars habitat that can sustain itself without constant inputs from Earth.
I suspect this is because the most casual analysis reveals incredible difficulties - the structures would have to be buried under a few meters of regolith to avoid constant radiation burn, and the ration of human living space to plant growing space (for food) would have to be about 1:6 I'd guess. The amount of material required to build such a structure for 100 humans? Let alone maintenance, etc.
If realistic plans were actually presented no doubt everyone would start laughing, which is why we haven't seen any mock-ups, VR models, etc.
They're working on getting the issue of transport sorted out first because the entire architecture is shaped by the constraints and requirements of your transport system. The amount of mass you can land, the energy needed for ISRU and so on.
HN just has forgotten its hacker roots and instead gets off to unconstructively sitting back and criticizing with shallow gotchas.