"Because we are" would be terribly narrow-minded of me. But it's sorely tempting.
We have to do a lot of research for our beliefs, since our beliefs don't come handily in an all-in-one answer guide.
Also, a lot of Pagans believe in the Threefold Law, stating that anything you do comes back to you times three. If we were to be intolerant or unreasonable, we'd receive that times three (or many times, if you wish to be figurative).
Thank you for this question.