Not true. It comes down to the luck of the draw. My L2D has rings.
I think people are selling them off mostly due to beam quality (rings). Others are selling them because their expectations are too high. The Cree is brighter than previous Luxeons. On paper the lumen output is nearly double given the same power supply, but actual perceived improvement is small. I've compared my L2D against my Surefire U2 and my HDS U60. The L2D is slightly brighter than the U2 (which is brighter than the HDS) and throws slightly farther than the HDS (which throws farther than the U2), but the emphasis is on the word slight. This is an evolutionary light, not a revolutionary one.
Of course, it's much less expensive than either. For the price, the Fenix LxD series is a good value. It'd be even better if they had put a nice orange peel'd reflector in there.