Reasons for this may be bad reservation policies where student of SC and ST gets admission in some good colg. on securing just 35-40% marks whereas general students are waiting for their chances even on 85-90% marks.
Other reasons may be corruption, nepotism etc.
THE DISADVANTAGES OIF BRAIN DRAIN
1) The national economy will fall. 2) The govt. giving scholarships to the Indian students and the students draining our national economy by the scholarships and giving their income to other countries. And they are paying the taxes there by that the income via income taxes is stopped. 3) Then the inflation is also due to the same matter.
But it has got some benifits also:
1) Reduces employment particularly among educated people
2) helped in acquiring close relations between India and USA on Silicon Valley matter in USA.
So, in the nutshell, acc to me, educated people should go to other countries to carry out researches etc but should not forget our motherland and try to server her.
Further, this so called brain drain can be stopped if better research and training facilities are provided in our own country.