I have a large amount of PS3 games. Around 50 or so. I also have a larger amount of PS2 games, somewhere in the neighborhood of 100. And I also have PS1 games, only about 20 of those. When the PS4 launches, there "might" be 1 game that I may want to play. Most likely, it won't have any for launch.
If I can't play any old games, I am not buying a PS4 for launch. If no games come out for a while on the PS4 that I want to play, it could be a while before I get it, if at all. The hype will lose steam, and I will just continue to play my backlog of games I already have.
I purchased a launch PS3 because it had backwards compatibility. No other reason. I bought Resistance with it, but I never played it until much later. The first game I played on my PS3 was a PS2 game. I was happy, because it meant that I could have 1 system hooked up to my TV and play all of my games that I already owned. I was happy, because I thought the company was showing some loyalty to the customers that were loyal to it and letting them play their old games. I continued to buy old PS2 and PS1 games along with PS3 games because I knew they would work.
When they removed backwards compatibility from the later models, I knew right away that they would be trying to re-sell the old games. They "hinted" that they were working on an emulation idea for it, but I knew that was a farce, only enough to string people along. (Much like the PSPGo and the people complaining about their catalogue of PSP games).
The point is they have already shown that they have the technology to have backwards compatibility. They also show that they don't want to include it because they make more money reselling games. What's better? Shelling out $50 for that PS2 game, or shelling out $50 and another $20 to play it on your harddrive, and having a useless copy on your shelf? Regressing technology is a stupid, stupid thing, and arguing for it is also stupid.
I have 3 PS3s. 1 launch system and 2 newer systems. I can't play all of my games in any room that I have them set up. I think this is particularly dumb (along with not being able to transfer save files and such, but that's a different). You say I can just hook up all the systems to my TV? How many systems should I have in my room? 2? 3? 5? How about those that play many different systems? Hell, I would like it if Sony came out with 2 models, one for the "poor plebs" that want a cheap system that can't do anything and one that is backwards compatible with everything. I would pay $700 for it. I payed $700 for the last one as well. But I won't pay for a system that can't play the games at all. What is the point? I'll just stay with the old systems and my computer. It'll be cheaper in the long run.
/rambling rant...