Here's the thing:
1. If you're dominated, you're screwed regardless;
2. Assuming you're not, the odds are you'll be in a flipping situation with a caller (which is to say, the chances of you being in a dominant position are pretty low);
3. Taking down the blinds and antes in this case increases your stack by more than 50% (even more in our scenario with the EP limper)...so....
4. Yeah, you go all-in not minding a caller, but to me, in most cases limping makes it way too likely that 3 go to the flop, and you don't want that with a middle pocket pair. The bottom line is that this deep, you can't really be putting chips in and then folding, if you are, in fact, playing to win.