I'll be the first to say that most of the EX characters are fucking broken.
Second of all, "up your game" isn't a good retort. There have been MULTIPLE iterations that have EX chars in them. Don't you think if ArcSys wanted them to be competitive they would have put them in the arcades? ALL chars in SSF4 will be DEFAULT. Their inclusion is intended for competitive play.
Why follow Japan's rules? Well let's see, where is the largest, most important tournament for GG held? At SBO, in JAPAN. What if someone wants to go compete there? Are they going to take their EX SKILLZ to Japan? Don't you think it'd be easy for the Japanese to run a console tourney? Believe it or not, they PS2s also.
Have some fucking sense.