This game is underrated by most, due to the fact that a good majority of the people on this forum cannot be professional
Anyways, Supreme Commander and Forged Alliance are both great games. The epic scale of the maps is almost unmatched, the strategy involved is also on a grand scale; you can flank, scout, sneak; and the graphics are also terrific. The only gripe I seem to have is that I would have liked to see more variety within the 4 races, such as different game-play mechanics.
I guess the reason most people would give this game a bad score is the fact that their PC can't run a game of this caliber. But you have to understand, that's your PC's fault, you should have looked at the requirements before even thinking about installing this behemoth.