The majority of highly skilled & excellence seeking technical people leave the country because of lack of opportunities/ places/ resources to continue their excellence here. this is true even of fields such as genetics, environment engineering, etc. There is no dearth or overflow of patriotism - it just isnt a part of the professional consideration. In many fields there is only 1 centre of excelence in the coutnry (if that e.g. ISRO) & they are govt. run - with few seats & a life not commensurate with the achievements ...
