Hindus consider cows sacred, so yes, comments that seek to insult Hindus with references towards cows should not be allowed for the sake of civil discussion on the forum - this is not a good analogy though.
A better analogy to Indians participating in discussions over Pakistan's blasphemy laws is when Pakistanis participate in discussions on India passing laws against the slaughter/consumption of beef or restrict freedom of speech in other ways. There is nothing wrong with Indians participating in a debate on Pakistan's blasphemy laws, provided it is done with civility and seeks to promote constructive discourse.