The greater modularity, lower cost and higher availability of the AR-15 platform made it a solution looking for a problem in the US.
I have one of the Howco imports with an S&H sear in it, and it barely ever gets shot. Yes, it's a piston-system (closer to the FAL than the AK in that regard), 0-1-3-A factory side folder that takes STANAG magazines, but it just doesn't do it for me. Not even when I put the rail on and mount a red dot or holosight.
Sweden still uses it, or a near clone of it, in their AK5 infantry rifle.