Why do people hack?

Counter-strike is and will always be the game where you can find a lot of cheaters, in my opinion, because its one of the first person shooter games where you actually have to be skilled, you cant just go like crazy running and shooting like in other first person shooters games, you will have no accuracy if you do that, since its somehow dificcult to control recoil and aim ppl often choose the easiest way. (cheating) Weak ppl in my opinion.
The other reason is due to rank system, they all want the highest rank, no matter what, rank system was a nice implementation but with it more cheaters came also.
Solution? Client side anticheat system, is much more efficient than VAC. ESEA uses it and obviously is not 100% cheater proof but at least you have less cheaters, actually Ive played so many times in ESEA servers and I can say its difficult to find one.
This has been discussed a lot in steam forums but theres always the ceptics that answer something like: " I dont want any software scanning my files "....."I want my privacy!". Usually I just say ---> Unninstall windows then! :- )
Theres a lot of controversy regarding this subject but a lot of demagogy also, they (VALVE) know the solution but they wont solve it !

P.s. - Sorry any bad english tried my best :-)