Why did this Iraqi army brigade swap its American Abrams tanks for Russian ones?

In my opinion the Iraqi Army could not maintain a child's bike. There is simply no maintenance culture in their Army to maintain a beast like the M1.

The Iraqi's know the Russian weapons better than ours, less complicated, and works for them, and the rest of the Arab states that can't read and write.

Because the ability to maintain and sustain the NATO and Russian based weapon systems is more feasible, reliable, sustainable, and accessible.
And what does Obama have to do with this? The initiative of US foreign military sales to push as much of US military capability began under Bush. And even then, the Iraqi military was pushing for NATO specific weapon systems from 7.62mm small arms and crew serves to smaller, lighter, diesel based vehicle platforms. The Iraqis were not a fan of our Humvees and M16s. They even rejected the M9 pistol and were issued (if my memory served me) the Walther P99.
I observed the same distaste of US military equipment by the Afghan National Army. Too expensive,too difficult to maintain, too big and heavy for the terrain their commanders argued.
This is not at all surprising.