It seems like it's unfair to say "Apple are late with OpenGL features." The third parties could put the same effort into making drivers for OS X that they do into making them (and their crapware frontends) for Windows, but they don't. I may be wrong, but it appears to me that it's Apple doing most of the work.
There's not much hard information on how Apple deals with graphics drivers, but from what I gather they use a unified in-house OpenGL frontend for the hardware-independent layer, then defer to a modified version of the vendors driver for the low-level stuff.
Their frontend only implements up to GL 4.1, so even if the vendors were to release drivers independently there would be no way for an app to access the newer functionality through the OS X frameworks.
I just replaced a dead drive in an old Mini with an SSD, then installed Yosemite. I'm not really an Apple guy, so I was not aware that Yosemite implemented kext (driver) signing, which had the side effect of 'breaking' TRIM support for 3rd party SSDs. It was never supported to begin with, but prior to Yosemite you could enable it by changing strings in the kext; doing so now will render the Mac unbootable unless you globally disable kext signing. Apple does not offer any other ability for a 3rd party to write their own driver to make this work, short of possibly rewriting the entire AHCI stack, which is not feasible.
