"With very low per capita income in India I think language issue is secondary"
Flip that around for a while. If the language issue was made primary, you could literally speak any language and have access to quality education and higher-paying jobs.
Just read an article yesterday that said that 60 students were expelled from the IITs - one of the major reasons being that they could not cope with English as the medium of instruction: http://economictimes.indiatimes.com/industry/services/educat...