Riktoven,
I wasnt picking on you, just stating a fact. If you pick up a M14, M1 Garand, HK G3, or most any other "combat" rifle, I think you'll find the 13" LOP to be pretty much the norm. Some are even shorter.
I wasnt bashing the AR's, I have a few and like them just as much as my AK's. I'm just not a fan of most of the sliders you see on them these days. Most are junk, and the good ones are pricey, but then again, you usually get what you pay for.