Why?
I would note that Dr. Kalashnikov was upset when USSR replaced his 7.62X39MM with the 5.45MM. I would further observe, inspite of all the praise the AK-74 received in USSR/Afgah War, the weapons fame apparently did not carry over to modern day. Specifically, I saw very few examples of the AK-74 on TV during our battles in Afgh. Lots and lots of AK-47s, but few if any AK-74s. All my readings seem to back up this conclusion. Likewise for Iraq. No real explanation as to why/what happened to all those the Russians left behind in Afgh.
Also, most of the AK-47s I have observed/read about in Iraq, seem to be of Russian manufacture-or copies thereof. Most seem to have the underfolding stock. I HATED the one I had! I still prefer a full-length stock. Damned underfolders rattle, shake, vibrate,etc.