Afghan miltary to be issued M16s, not AKs

From the Times Online:

[N]ew recruits to the Afghan National Army (ANA) are being asked to swap their beloved Kalashnikov AK47, probably the most famous weapon in the world, for the American M16.

This seemed quite unusual to me, as the AK-47 is quite common in that region of the world, and many of the Afghani soldiers have a degree of familiarity with the AK.
The reason is explained as follows:

Traditionally, the Afghan will fire his Kalashnikov from the hip as he advances, spraying the enemy in all directions on automatic mode until every bullet has been expended.
But that is not the way of the British or American soldier who uses his ammunition stocks with greater husbandry and fires to kill, rather than to deluge the enemy with a wall of bullets.

The M16s the Afghanis are to be issued are equipped with the three-shot-burst fire control group (justt like the US military M16s), rather than the full-auto group.
I know the Israelis use M16s (or at least I’ve seen cute female IDF soldiers with M16s), and the US military uses M16s to great effect in sandy, desert conditions (yes, there have been issues, mostly due to lack of proper maintenance, but overall the M16 has performed very well).
While equipping the Afghan military with modern, accurate, standardized weapons is an admirable goal, I can’t help but wonder what strings were pulled to make the sale. Couldn’t they equip existing AKs with three-shot-burst capability, or simply buy new burst-fire AKs, rather than completely changing to a new weapons platform?
As they say, follow the money.