By raising the "threat," our government is saying "wake up people." Pay attention to what is going on around you. You never know when you could be the one that spots something that is out of the ordinary, or out of place.
Everybody complained that we did nothing last time we had "intelligence" of a terrorist plot against americans. There was an uproar that the public was not warned. Now, they do something and you still complain.
Come on. I see your point, but I don't think it's a good one. The government now has come up with some automatic system they can fall back on should something happen. Truth be told, they don't know when the hit will occur or else they would stop it. Having a terror alert system is nothing more than a permanent poster they put on the wall so in the future they can say, "Hey, we posted that you should be on the lookout." No matter what level, it still grants them the opportunity to say, "We had a warning out." It's stupid that we paid Tom Ridge all that money and then he comes out with a color wheel saying this indicates how scared the government is at failing to recognize terrorist attacks. Did I, or anyone I know, do anything differently today over yesterday now that we are orange (or whatever color it is)? No. Nobody cares about the color chart other than the government or the media. The media is dying to get anything with the word terrorist on the air, so of course they are going to report it. It does nothing for our country, that I can see, other than warn that the government is scared of possible attacks. I guess the color wheel is so that you can be assured of how scared the government is.