Well, here is the truth and especially rampant in IT. The article is well intended. But it does not work in India.
Presumptions:
1. The candiates are of very similar experiences. 2. Both candiates are considered to be more or less of same caliber.
A Tamil will always promte a Tamil, so also a Punjabi, a Telugu, a Bengali, a Marathi. I have been over 5 yrs in North and over 5 yrs in South. But I find the bias is rampant in South (at the same time North is no saint - but less evil in this respect)
There are expeptions, like if you are an incredible performer and the work you do can be by very FEW. This is in Product companies based in foreign - but there you have individual performer role and actually management is some GORA. And you know how much they scuk. Management by Indians is literally non-existent.
In IT services or Indian IT prdoduct company, never ever think that you will be promoted as manager for your performance. Never ever think that you will be promoted over another peer who speaks the native tongue of the supervisor. The language divison rules. And hence the attrition (other reason being salary hike).
So, why they do it?
They feel comfortable. Of course, native tongue is most comfortable one.
Now will learn all the langauges in India. (15 or 18 or 20 or more??) Good lord. It is difficult to completely master even "C" language in 9/10 years, forget learning 20 languages.