There are just some players that get more hobby love than others........Ruth, Cobb, Mantle, Speaker, Mathewson, Walter J, Clemente, Gehrig, Ted Williams, Koufax.....
There are some baffling examples though of greats who don't get as much hobby love as they really deserve....the most glaring example to me is Frank Robinson....he truly was one of the great players of the game (check out his HR, hit, RBI totals) yet his cards can be picked up on the cheap, relative to his contemporaries.....which is great for collectors