–Baseball has a tremendous emphasis on individual performance. When you strike out, everyone can see, and some kids come out of the batter’s box crying. Hitting is *extremely* hard, as is pitching to a four-footer. Really lousy baseball players are more marginalized and embarrassed than really lousy soccer players. Soccer is more "everybody run around," although of course individuals matter.
–Contemporary parents are obsessed with safety. Soccer is perceived as safer, and may well be, at least until the kids get a little older and start banging into one another harder.
–Girls seem to like soccer better, and co-ed soccer seems to go on longer than co-ed baseball, perhaps because girls can compete more effectively at this sport. My son’s little league is already probably 97% male, and he’s only 8.