If all the major sports leagues did away with your all star games, and only kept the teams as a fictitious thing(like the Associated Press All Pro rosters.) than yeah, the stats should be the benchmark exclusively.
But these games, no matter the stipulations added to them, are for the fans. Everything is a popularity contest. If some of these lesser known players stay consistent and put up number for multiple seasons, they'll get their just due. It never fails. I know I wouldn't wanna watch if the starters were a bunch of young guys who haven't been great long enough for me to know who the heck they were. Not every fan devotes all their time to a sport, so you can't expect some of these "deserving" baseball players to get the respect that a known player gets.