I wasted almost 10 years of my life in FPS's and was at one time top 10 world ranked, way before cheating became as pervasive. Anyway it is so easy to learn the maps and control points that you appear that you are cheating. Now days I would say that cheating is more of the norm than not and that is just one (more) reason not to waste your life on them.
THIS^^^ there are school kids that play SO much that they know more than the guys that designed the game. They appear to be cheating but you would say the same if you played Mike Jordan in one on one and didn't know better.