Yo Brady, I too would like to fly, what to me, are "exotic" planes. The bottom line, however, is that this is a game that requires continuing payments, hence it must hold the interest for the great majority for an extended period.
One of the primary ways to achieve this is historical events. The "lovelys", as I will call these cool but limited use planes, should be a part of the game(as they are), but the main thrust must remain to fill out the planeset with all of those "common" planes that provided the bulk of the action for the largest market for the game. The "My Daddy, Grandpappy, I, flew it" syndrome.
Please don't take this as parochialism or ethnocentrism; it is simply common sense and good business.
Lizardking
P.S. Funked- For a WWII flight sim to not have a B-25 is akin to the same game not having a Mustang, for the bomber types among us.