One of the promises made by the Zoroastrians to the Hindus when we came to India is that we would not slaughter cows or eat beef.
Am happy to say that even though today 1300 years later there are Parsis who do eat beef, I have never seen beef cooked in any Parsi home.
I do not know how it is for Parsis living in Pakistan of course.
And I think it is no secret to anyone who knows Parsis how much they love meat. Any kind of meat. And the copious quantities of it that they consume. Its not something new. Take a look at Iranian cuisine even today and you would find the same.
So yes, its something we do by choice, out of mutual respect for our land and our people. Not because its banned or taboo for us.