It's not a deal breaker for me. I find myself playing the games on original hardware most of the time.
The backwards compatability on the Playstation 3 and the Xbox 360 was horrendous, anyway. The only real way to include it on modern consoles is by either including the old hardware, or by emulating it (I hate that because it's so inaccurate.) If they were going to include BC in the PS4 they would have to basically include the entire PS3 hardware in the PS4 (meaning it'd be more expensive). I'm pretty sure a PS3 emulator will not run on the PS4, either.
Did you know that backwards compatability is something of recent years? Before the Playstation 2 it was basically unheard of. Other than SEGA and Atari, nobody really included it. Do you remember playing your Nintendo 64 games on your Gamecube? No. SNES games on your Nintendo 64? No. Maybe because I grew up with those generations it's not as big of a deal for me. Besides! Your old consoles aren't broken when you buy a new generation. You can still play old games on your old hardware pefectly fine!
The only thing that really sucks about having to use old consoles is that they don't support modern video outputs. It means you have to use composite or -- GASP! RF! Now that's some low quality right there! On the other hand, retro gaming is really wicked! Yeah, it's totally rad! ... *sighs* I'm too old for this.