Having spent the past year commuting on 450's & 444's I can confirm this trend of more uncomfortable seating on modern stock.
The reason? Certainly in the case of 450 & 444 its capacity, with 450's by far being the worst. The 450's as I'm sure some of you will know are 5 abreast - two on one side, 3 on the other. Its a nightmare! If you're unfortunate enough to be sitting on a 3 seater arrangement in rush hour you're certain to find the middle person having to lean forward whilst the surrounding two people sit bolt upright. Just check
http://www.no450.co.uk/ for an idea.
Stu