That's an ad hominem argument; almost a textbook case of one.
It might make a tiny, slim bit of sense if the "celibate" in question were making up something out of whole cloth. In this case, though, he's just reiterating for you what had been the constant teaching of the whole Christian community up until 1930. It doesn't take any special understanding of marriage to do that.
There are also plenty of married people who will tell you that artificial contraception is a bad thing. Does their opinion not count?
As opposed to what? The Halo argument?
It’s more like asking a lifetime vegatarian for a good roast recipe.
An ad hominem deals with a characteristic of the person. So if I said they’re fat so I don’t take sexual or marital advice from them, than that is a definitive ad hominem, also somewhat grayer is if I say that they believe in God, therefore I don’t trust their advice on sex and marriage, that is another ad Hominem.
But they are celibate. Meaning they vowed specificaly to not have sex or marriage. So, it addresses the point.
Therefore, no ad hominem.