Yes it's not a normal C&C RTS game. Before it was released it was being made as C&C Arena. It was supposed to be an online game only. Which matter of fact would have been a much better choice.
The wrong part from the developers was when they thought at the last minute to make this into a 'full' game, and at the last minute just scrapped together a short boring campaign and called it C&C 4.
However, if you look at it as just C&C Arena and love online games, then go for it. It's actually lots of fun playing this game online.
If you wanted to see the 'epic conclusion' like most of the fans then yes, you will be disappointed. But it's too late to change the game now, play it for what it is and have fun.
Another detail that proves this is supposed to be an online game is all the fun Achievements, this game has lots of Achievements you can try to harvest, just like every modern online game now-days have. Give it a try.