sony sucks. 
Yeah, Sony sucks, but honestly the amazing level of complexity in modern consoles makes backward compatibility hard to pull off. When a new machine comes out they either have to more or less build the old machine inside of it (what Nintendo usually does with Gameboy stuff), make an adaptor that basically has the old machine inside of it (Master Base Converter, not very cheap) or you have to do it with emulation. Unless the time between generations is very large, then the hardware you have to build in is going to cost some significant money, or the emulation is going to suck. The 360 is in a similar state, although its less relevant given that there are only about 5 good Xbox games anyway and the system is worth about $0.50 now.
The PS3 is already a huge money loser so I imagine they are doing whatever they can to get that kit-bash monster to a reasonable price. What they should have done, what Nintendo always does, is look further down the road during the design phase and have a plan for making the machine cheaper as prices on components drop. They probably never should have put PS2 compatibility in it in the first place. I just don't see how Sony will ever be able to make a $129 PS3.