A very interesting question. Blaming will not solve anything.. so it's upto you if you would like to blame somebody or not…But before reaching any conclusions let us see the scenario in India..
Indian academic picture is very bleak at this moment. Why? Well what can a Ph. D. Student can do after his/her degree… two options either he goes into academia or industry. As much I have seen a major chunk would like to stick to academia. If he goes to academia he will have two fates either he goes to post doctoral system or he gets a job in academia.
Academic job- academic jobs are scarce and usually ends up in the lap of somebody who know knows somebody. Please mark my word I said usually not always. Every supervisor wants to help his student and I don't see anything wrong except fairness in system.
Post doctoral fellowships- Indian system of postdoc is absolutely rotten. You can usually count the number of different fellowships available. I think it becomes more difficult for liberal arts than science. Well even if you get one your fellowship will not reach you in time. You might get fellowship in time gaps. The funding provided is very less just for nameshake. And if you belong to general category you have no fellowships to apply for after 35 years of age.
Now let's see why people go abroad. You get salary/ fellowship regularly. What you save there become multiple times when you come back to India. You are not bothered about experiments, enough support for your ideas. People prefer to give jobs to applicants who have done postdocs outside… even if there are better guys who have worked in India. So this mentality of desi and videsi still remains embedded in our minds. Most importantly there is no age limits as such for postdoctoral work.
Now you decide if you would like to blame them or not. Hope I answered your queries.
Edit - I have not taken other variables like NET, GATE, Reservations in the answer. If these variables are taken into consideration the whole answer will change.
Niladri B Kar, former Unemployed Zoologist Answering Quora Questions