Good to know that "making Nintendo more money than if they released only one version" is not something that should be considered, at all. It is impossible for Nintendo to make the same amount of money with only one version; they wouldn't have sold nearly as well with only one.
Well honestly with this set up it just works, Pokemon is a pretty big social game in a sense of trading and battling. Would be pointless not to have two different versions of the same game. Hell even the 3rd games tend to require you to need one of the other games.
But hey there is no denying that the series is milked, but main games not so much compared to other main games in other series.
"Gamestop will not be around in 10 years because physical games will no longer exist, it'll all be digital" Xeeh_Bitz