The problem lies with the way IIT's are projected when students are taking coaching. Up until a couple of decades ago, they were projected as premier institutes for the intellectual cream of the country ( and they were too, mostly). Now this cream naturally ended up with lucrative jobs and packages and in the current generation this has been projected as the main selling point of IIT's by the despicable coaching institutions.
But once the student slogs it out for 2 years or more, particularly if you are from one of the several coaching institutions ( referred to as factories by professors) in AP or Kota, and the student enters IIT, they see that it's not all rosy. There...
more... are no 1 crore per year packages or companies lining up to take them in. The only department meeting such inflated price tags is the Computer science department, and most of the buyers being MNC's from the US. So, the next step? Do a Masters in Computer Science, end up in Silicon valley, getting 100 grand a year.
The root of the problem? Very few engineers in the present generation take pride in the impact of their work on the society. They are simply not taught to think on those lines right from school. If that is not tackled, engineers will continue jumping to other countries only looking for how much their job is paying them. :(