The problems tend to be;
They spend way too much building them
They are huge ( mainly ) with pokey rooms
I bet they are a nightmare to maintain and heat.
Cleaning would be impossible in some, thinking off really tall high places
I look at some of the light fittings and I think how the hell are you going to change those bulbs.
They make them far too personnel, never thinking of resale.
They tend to follow the pattern of timber cladding, walls of glass, and steel beams every where, they are not original anymore.
They look cold, stark and lack anything that makes them homely.
They are ugly.
I know of 3 grand design houses built all so eco ground heat pumps etc, they all did 1 winter then put gas central heating in.