If that's not a rhetorical question, it's one that should be directed to Adobe, Tony. We're just fellow users, so we have no idea.
Just more of a venting than anything else and hoping maybe Adobe may see this? Also, I don't see a lot of insights from Mac users, so I thought I'd let my fellow users know as well if they are thinking about making the move to PE.
This disparity has been discussed several times, in the Premiere Pro forum. Adobe points out differences between how the Windows OS and the Mac OS, as the reason - some Transitions and Effects just do not work on a Mac.
Though this list is now a few versions old (PrPro CS 4), it covers what were then the differences. As of PrPro CS 6, some of the PC Transitions and Effects have also been eliminated, as some would not work with the MPE/CUDA graphics, even on the PC: http://forums.adobe.com/thread/460313?tstart=1470
Adobe has been able to port a few more over to the Mac, but not nearly all of them.
Very interesting. Thanks for that. I am not a programmer or coder, so I would have thought it would not be an issue, but I guess it is.
Many voiced similar thoughts, but the Adobe engineers, who responded pointed to how the two OS's handle graphics, as being the main issue.
Over the decades, I have seen a few of those differences, but those seem to be in favor of the Mac, such as being able to change the Cursor color for many Photoshop Tools, in the Mac, but with gray being the only option on the PC. I have always envied the Mac's capability there.
Like you, I am neither a programmer, nor coder, and was a bit surprised, when those differences first surfaced (in PrPro CS 3 - the first "Pro" version of Premiere to be ported for both platforms). I would just have guessed that it was probably the other way around. Way back, before the Pro version, Premiere 6.5 had some Transitions (and maybe Effects?), that existed only on the Mac. Not sure if the PC also had some specific to the platform, but probably. PrPro changed things greatly, but was only for the PC, from version 1.0 - 2.0.
When CS 5 came out, with full MPE/CUDA support, everyone lost a few "old stand-by" Transitions and Effects, as they could no longer work. Some were replaced by similar, but a few just went away for good - on both sides of the street.
One could get more background, by doing a Search for Transitions on the PC, and looking at Todd Kopriva's comments at the time. Many of those articles go back to PrPro CS 3 & CS 4, but should still be on that forum.
I wish that I had more to offer, or perhaps hope that the Mac would get other, similar Transitions and Effects, but with 2.5 versions later, it still seems to be the case. Though it has no MPE/CUDA, PrE obviously falls into the same arena, as its "big brother."
Not sure how it might be with 3rd party Effects and Transitions, say from NewBlue FX, Pixelan, ProDAD's Vitascene, or Heroglyph, but it might be possible that one could work around the differences, with plug-ins from them.