You are really asking why there's a restriction in place for a Pakistani to get an Indian Visa? Ok. There have been certain attacks on our citizens by people having links to Pakistan based handlers. This has complicated the issue and created an environment which isn't trustworthy. Hence restrictions.
Now Pakistanis want to come to India because they want to save money (not because they can't get treated in Pak, it's just that it's kinda costly there) so they prefer getting treated in India. Now since there's a restriction in place (which is both ways), it makes it impossible for them to obtain an Indian visa.
Now, to speed up the process, they contact Sushma on Twitter. Sushma REPLIES (even though it it isn't her job) and GETS THE JOB DONE FOR THEM.
She DID NOT contact any Pakistani to come to India.
Now please tell me, what went wrong on Sushma's part?