I worked with an Indian lad in my last job, born and raised there and here on a working VISA and I asked him how a country of nearly 2bn people can't string 11 half decent footballers together
Answer he told me in effect was the dominance of Cricket - It is bled in to young boys the minute they are out of the womb, Cricket is probably bigger in India than football is in this country, PE in school is just cricket practice in effect, all the government money into grassroots sports goes into cricket (Knock on effect of that is a limited number of proper pitches and professional coaches), kids in Indian schools who would rather play football over cricket would just be seen as a bit odd
He did say however just one Indian player playing regularly at Premier League level for a decent side, very similar to Son in his pomp at Tottenham could change things, Indians are very fanatic and one figure to inspire the kids of today could work wonders for the growth of the sport there