This is why it is still by far the most accepted theory in academia and it makes the most sense (wishes of Indian nationalists not-withstanding).
Also, just curiously... how do you get an Indian origin of the Indo-European people out of the link you posted? From the summary, it states nothing of the sort and merely confirms that there are genes in common between Europeans and some populations of India... a fact most everyone agrees on. More endogamy doesn't imply origin by any stretch.
http://en.wikipedia.org/wiki/Indigenous_Aryans
"Politicized theory". Not accepted by mainstream academics. Most likely not how it happened. Please don't confuse nationalistic pride with reality.
Don't ignore the evidence!
I do know what an abugida is, what are you driving at?