I really, really, really don't understand this thread. Allow me to clear up any further confusion:
YOU CAN MAKE FULLSCREEN GAMES. YOU CAN ZOOM THE SCREEN AND CHANGE THE ASPECT RATIO WITH EVENTS.
And yes, you can even use events to auto-detect if a person has a 4:3 or widescreen resolution, and change the size of your playing area!
Case closed, and thread closed.
(P.S. - if you need any actual help making your aspect-ratio changing events, please feel free to post your attempts in Help/Tech.)