**I did not see the article mention for instance, Matthew 13:54-57 which specifically says:
54 Coming to his hometown, he began teaching the people in their synagogue, and they were amazed. “Where did this man get this wisdom and these miraculous powers?” they asked. 55 “Isn’t this the carpenter’s son? Isn’t his mother’s name Mary, and aren’t his brothers James, Joseph, Simon and Judas? 56 Aren’t all his sisters with us? Where then did this man get all these things?” 57 And they took offense at him.**
I remind RCs of that passage all the time. How could an only child be viewed as so shockingly different when compared to the rest of the brothers and sisters,......if there were no brothers and sisters? Those folks had seen them all grow up. They couldn’t understand how Jesus could have turned to be the man they were seeing and hearing.
It’s just like the devotion to praying to Mary, but NOT to the woman from Canaan, or the centurion that asked the Lord to “speak the word only, and my servant shall be healed’; both of whom the Lord praised for their show of faith. (of course the praying to those asleep in Christ is another one of the RCC hangups.)
One of the claims is that the term "brothers" of Christ is used in a spiritual sense.
But the people of Nazareth here weren't speaking spiritually. They weren't even aware of the existence of a spiritual brotherhood, and wouldn't have believed in it had they been aware.
The other explanation here is that "brothers" means kinsmen. Well of course it could, and still is used that way today to some extent. But it seems odd to assign the looser definition when the simpler meaning makes perfect sense.