Why isn't there a horde mode for this game all the stuff is there for a good horde mode aliens, good maps and **** loads of ways to kill em

This being their first foray into consoles and all multi platform development was handled completely in house, they need to focus on getting the features they do have working properly.

Have you even played the SP? The AI is retarded. Nowhere near as smart or fun as Reach or Gears. They're really just barely more sophisticated then zombie AI.
The AI has to improve drastically for a Horde mode to work well.

Perhaps for Crysis 3

If you play on superhuman the AI is actually quite efficient.

super human i find is no different than normal you just lose energy quicker when shot and armor mode on.