As has been said, it's money saving.
From memory with Nvidia the hardware is still there, but they don't want to pay to maintain the drivers for the 32bit implementation.
Another example with computers is the humble PC speaker.
It used to be standard in all cases, then motherboards started having them because it was realised that for system builders etc it was handy to have it on the motherboard, now there is no guarantee that the motherboard or the case will come with one (I've got a box of cheap ones* that I had to buy a few years back when I realised that neither an expensive case or motherboard had one).
I loathe the way standard functionality is being degraded, as an example every £30 DVD player used to have a full size remote and a screen that gave you useful information on what was happening with your player (if it was playing, how far along it was, if there was an error), now even a £300+ BD player maybe has two LED's to show it's powered and playing and a remote that has unusable buttons if you've got any issue with your hands because it's now the size of a box of matches (seriously, I've bought two new players this year from different manufacturers and both had remotes that would have been considered small and barely usable on £25 Aldi specials 10 years ago).
Same with phones, I'd much rather a phone that was 0.5mm thicker and last a full day than trying to get it thinner and thinner by removing battery capacity.
*It was something like £6 for a box of 25, delivered from a retailer, so maybe 5-10p per unit if a manufacturer was including them in a case/motherboard that cost £200 or more RRP.
