Yes. Young boys are immature. Even adolescents would react, to an extent, the same way. I myself am an adolescent.
I think the use of altar girls is one of the reasons that has led to a decline in priestly vocations. When girls volunteer for serving at the altar, boys, whether out of immaturity or something else, don’t volunteer nearly as much, unless they’re voluntold by their parents or something. When boys don’t serve at the altar, they’re missing a critical step in making the decision to become a priest. If a boy is on the edge and he is offered serving at the altar to “try it out” and he actually does it, then that boy may very well go through and become a priest. It’s like job shadowing. However, if the young boy is like “eewie” and doesn’t do it because his sister is doing it, then he loses that experience, an experience that may well, as I said, make him want to become a priest.
This is primarily the concern of the nature of young boys. ** They don’t want to do things that girls are doing, because either directly or indirectly, it feminizes them in a way. I’d venture to say that, as a male myself, this continues for a male’s entire life, but perhaps lessening a bit with age. Males are concerned with maintaining a manly image. **Serving at the altar with girls, in some ways, threatens this image, especially for young boys. Now we can argue that this is just pride and blah blah blah, but the fact of the matter is that we aren’t going to change the nature of young boys by arguing about it.
Therefore, I stand by my opinion that the institution of altar girls is one of the reasons that there has been a drop in priestly vocations, because, through their own nature, it makes boys not want to do it, depriving them of the one experience they can have of doing some of the things the priest does.