Hi Guys,
I tend to think the real problem is that all these software sample players etc cater to the sequencer based user. Sequencers can obviously cope without program changes. Not having used any of these software sample players, I can only assume you assign an instrument to each track ??
Majority of users of these sample players, would probably use them for recording purposes be it for midifiles, mp3's cd's whatever. There's probably no great urgency for these companies to incorporate program & bank changes into the program if they work as is, for the majority of users.
Let's face it, it's us realtime arranger /softsynth users that are the odd one's out.

Meanwhile at least we have the opportunity of having great Lead/Melody voices using these sample players.

best wishes
Rikki