Flew the A350 and 787 a week apart (recently, via Qatar) - the A350 is a surprisingly quiet machine on the inside.
The 787's larger windows (combined with being tall) means I get an almost 360 view around the plane through windows around me over people's heads (until they dim everybody's windows by default * shakes fist * )
The reason for the tinting is really simple - weight. You have to be able to shade the windows and doing this way is less weight then have pull down screens. Everything in aircraft design here comes down to weight reduction.
I also think giving crew control is a factor. Rather than asking/telling individuals to open their shades you just control it. I guess this makes compliance with regulation easier.
Lets say there are 52 windows and each shade weight 2 pounds which I don't think they do. That is 104 pounds on a 380,000lb aircraft. That is .02% of the weight of the aircraft.
