I do agree with you to an extent. The more fleshed out the junior/int'l leagues get, the more interesting franchise/GM modes become. Next gen provides the storage capacity/room to let that happen I would think.
Right now though, the game has more modes than most people know what to do with. It's great that there is something for everyone whether it be online leagues, HUT, BaGM, or whatever... the selection is awesome. Some of those modes do need some tuning but the main focus should be on gameplay. Improve that and the game as a whole becomes better and that gives the devs room to then tinker with the individual modes. If they can improve AI, eliminate any super goalie type play or all skaters feeling the same, and allow a wider range of tuning with expanded sliders, the game will be a lot more fun no matter what mode you play.
