That's because of the boorish behaviour and sense of superiority displayed by a certain section of the public. These people will not show off in front of a westerner.
There always was an underlying sense of Hindutva which never really got national prominence due to the ruling political parties. This is not always to the credit of the politicians, but its just that the voting patterns ensured that manipulative politicians who professed to be secular got to rule India.
All of a sudden with the rule of BJP a sections of Indians did not become pro-Hindutva, rather the ruling BJP allowed the flowering of this sentiment. This is similar to the internet fueling our dark fantasies and at times even revealing detrimental aspects of our behaviour which we did not even realise.
Do you really think that Pakistanis on PDF became anti-India due to BJP? Not at all. This anti-India sentiment was always there. It got a fresh impetus because of the overall dynamics of the Indo-Pak relationship. How many Pakistani members keep thinking that the Pak armed forces are superior to the Indian ones? Our armed forces are as dumb or intelligent as our masses. So why do we keep thinking that our armies have the highest standards of thought processes?
The PDF management has allowed these anti-India inflammatory and mocking posts from Pakistani and Chinese members for reasons best known to them. We can guess though.
I can be very courteous to you but totally against your way of life, and think that your way of life, religion etc are thrash. Is this thought process of any value? An an example, Europeans are courteous towards us, but don't they exhibit a look-down-upon attitude towards us? Just because Pakistanis talk well with a boorish section of Indians, it does not mean that Pakistanis are intellectually better. The way your ruling class has managed to run Pakistan is testimony to how smart you are. This simple aspect needs to be understood.