Alain, I used to have a Sony G70 - so know the pain
Digital projectors are a huge improvement.
Manufacturers just need to get the gray scale tracking/gamma etc correct - which they don't, and have the usual color/tint/picture/brightness cranked up for regular customers and allow those of us that care being able to use something like Avia to adjust these. This would meet the requirements of the average Joe Public (a nice bright picture with rich color) and the enthusiast. My projector has had an ISF calibration, it is stunningly accurate - but again Joe Public would complain its too dark!
One idea would be to have a self calibrating projector, a small sensor built into the projector body and software that just went through a self calibration routine.