Never was a problem for the small parish I grew up in. That was because my dad considered it to be a requirement for me and my brothers. The other guy’s dad’s did the same thing. It was both a privilege and a responsibility. It wasn’t presented as “Does little Johnny want to help?” it was “We need help, can Johnny do it?” Some might not see a big difference in those two statements, but they mean very different things.
I don’t Michael was intending his statement to be subject to the rigors of statistical analysis. While some of it was glazed over, I defend his assertion because I have heard it from other channels as well where the question was put to clerics and seminarians about what experiences had a positive influence on them in regards to becoming a priest, and the connection with serving at the altar was one of the most common responses. Again not statistically rigorous, but it is something that sticks in the minds of the priests themselves.
Girls do drive the boys away from things like this. I remember when our pastor (from the parish previously mentioned) asked us if we wanted altar girls and all of us gave an emphatic no. This was our turf, our responsibility, and we didn’t want to share it. There isn’t the same camaraderie between the sexes as their is between men of any age (I’m sure the inverse works too but I’m not a woman so I won’t speak for them), and that is part of the appeal to the boys and young men. The point is we are trying to train up little priests (“little cleric” is the Italian name for altar boys), and so we give them all the attention in this regard.
I don’t think some of the responses here give boys (or girls) enough credit in terms of their love for God or the Mass… 
