Sony has finally decided to switch DualShock controller buttons to digital after keeping them analog for 16 years.
Digital buttons have two states only: pressed and un-pressed whereas analogue buttons are able to measure how hard and how quickly they are pressed. One of the few games that took advantage of this feature is Gran Turismo 5 where players control their acceleration by how hard they press the shoulder buttons.
It is hard to find other games that took advantage of DualShock 3's analog buttons; thus Sony decided that it is not worth the extra cost and the added complexity.