Firstly, everyone has to look at what is best for one's own team, independently of the national teams. Not everyone can train Indian players only
Secondly, even if one wants to, it is not so easy to get the right player for the right price. Some recent prospects have been priced way too high.
Thirdly, training is a long term process which takes patience. I do not believe that a NT or U21 coach has that much time to nurture fresh talent.
Finally, what counts is performance and, even more, service to the overall community. I have noticed much more activity and discussion in the last year than before.