Mascot mode is absolutley the reason thousands of people buy the game.
Its not my thing, I have watched my son play it. If the game was 9.5 in all areas but didn't have formation subs. Very few people who would buy the game would let no formation subs, stop them from buying the game. However even if the game is a 9.5 game, if there is no mascot mode, alot of people/kids will not buy the game. Their purchase dicision is based solely on mascot mode. Thats why its in the game and it will almost always be in the game.
Cheap way to get more sales. all mascot mode is is a 99 ovr play now teams with mascot uniforms and special juke moves.