I find that "I told you so" deeply problematic. The Muslims in India today had no say on where they were born. They had no say in the creation of Pakistan.
In today's India, Muslims are denigrated, assaulted and killed simply because they share the same religion as the Muslim rulers of generations ago and the people of Pakistan. What you describe, is simply an extension (or perhaps converse) of the same guilt by association proffered to Indian Muslims from the Pakistanis.
Let us also understand that Jinnah's concept of Pakistan was a safe space for South Asian Muslims to live, free from the ills of Hindu majoritarianism. It was never intended to be limited by the boundaries that we see today. Therefore, it would be unfair to criticize those who just happened to end up on the wrong side of Radcliffe's line.
In a similar vein, today many Pakistanis live a comfortable and financially better life in the US/UK than their brethren in Pakistan. Wouldn't it be considered poor manners to criticize and put down those who did not or could not migrate to greener pastures in the west? So why does such behavior elicit glee when it comes to Indian Muslims? Do Pakistanis need Indian Muslims to suffer to validate the thesis of Jinnah? By that same extension, do we need others to suffer to justify the choices we made?