Why dont buddies stay together? Is it because diver training is no longer stressing staying together as much as it did when I did my OW?
The degree to which it as emphasized in your OW class was very much influenced by the practices of your individual instructor. Someone being certified at the same location at the same time might have had a different experience.
Although it is obviously too soon to make a difference in the current world of diving, the new standards and procedures PADI is introducing this year into OW instruction greatly increase the emphasis on the buddy system, both in the CW instruction and the OW requirements. This is part of a number of changes based on their joint research with DAN that revealed that the number one preventable cause of a dive fatality (as opposed to, say, a sudden cardiac event) is initiated by a diver going OOA without an alternate air source (like a buddy) nearby.