They are in dire need of better industrial and mechanical design. Tubes sideways heating the row above them? The ugly color? Who would be proud to have this in their listening room other than price?
If they are going to make expensive stuff, it needs to be exquisite from mechanical to visual look of the product.
Aha! I quite like the styling, and whilst it is true that the higher valves will be hotter than the lower ones due to convection the actual heat dissipation is likely to be much better with this layout than with a conventional audio amp layout. Old high power thermionic valve kit used to be laid out to allow more effective convection cooling like this back in the day.
Actually styling is definitely a personal thing, and the quality of manufacture gives some pleasure in ownership (to me at least).
One of the things I liked about my Goldmund amps was the case, which made no sense from a SQ pov but was so much nicer than the bog-standard painted folded steel box with slab of ally on the front which everybody else was doing at the time.
Nowadays CNC machining is inexpensive and lovely bits of casework are not anywhere near as expensive as they were. I had a Linn Klimax DS on home demo and whilst it sounded no different to me than an item 10% of its price it looked and felt lovely.
The Devialet amps are beautifully made inside and out too, particularly the top model's case.
In the end I wouldn't consider anything this expensive any more, and certainly not with valves. It seems bizarre that analogue kit is so expensive despite having, in almost all cases, performances an order of magnitude or two worse than a £300 DAC.