If US Lax and just went by birthyear, the whole holdback problem would simply disappear and the playing field would be equal. That's all anybody is really looking for, a level playing field for their children. If your kid needs an extra year of school or to repeat, no problem but he'll still play with his birth year on the club circuit. HS, no problem, grades are mixed anyway on varsity teams.

There is no logical argument anyone can put forth as to why kids shouldn't play with their birth year (or up if they choose) so those defensive parents resort to taunting and calling everyone a snowflake that raises the issue.