I agree, Categories for GA's really don't do anything at this point. If they were organized the same way in DM that'd be one thing, but organizing them in the game center, when it is really only used for creating them, is pointless.
In addition, it is possible to create duplicate categories which clutters the page.
The ultimate solution would be to organize them by type, name, or category in DM. Not organizing by category yet by type or name still renders categories rather useless.