The door swings both ways. My son was an only child, it was not our intention, but that was the way God willed it, we had no say in the matter.
When the 3 of us walked down the ailse I could feel stairs on our backs. I couldn’t help but think the large families thought we were selfish, “they’re too wrapped up in their yuppie world etc.” It probably didn’t help my wife worked/works in a professional career.
Whether any of that is true or not I dunno.
It wasn’t all that bad when he was young but by the time he reached 10 we often heard comments, “your wife must be career minded,” “how do you keep from spoiling him?” “Having only one must be nice.”
Outside of the parish, we heard, “y’all must not be real Catholics.” in a joking manner.
It was not that big a deal becaue we learned to deal with it. But like the OP sez, it was just rude.