If the transition is made to bigger resolutions, games will generally become longer and the gap between a veteran player and a moderate player will decrease, because it will become (potentially a lot) easier to read the opponent's movements and strategies.

In tight levels where speed is pretty much the deciding factor (like bbswing), in most key-situations you can easily see which way the opponent's going to come at you with a higher resolution.

People could do well to understand that -- over the years -- gameplay has developed around seeing the standard 640x480 area and it will significantly mess up various areas of competitive gameplay if people start seeing a bigger area.

Sure it's nice to see a bigger area at once, and it could be considered more refined and an upgrade to the gameplay, but it has more downsides than people seem to be able to comprehend.

EDIT: and compromises like downtuning with a command won't make much a difference.