We can argue about this all day, but only time will tell. And I don't it's seen as a rich preppy sport, at least not anymore. There are 103 high school teams in the state of Michigan, and those aren't all private or rich suburban schools. Two Ypsilanti high schools have a team. Romulus has a team, so does Lansing Waverly. Public schools in Warren, Saginaw, and Bay City have teams. And lots of rural high schools have teams, and this is in a state that is still pretty new to the sport.
I'd argue hockey is a lot more of a rich white kid sport than lacrosse, and it's pretty popular.