Just because you’ve used a different sniper in each different game doesn’t mean you’re good with using a sniper rifle in all games. All of the games listed above are of much different play style and use different code. More than likely the reason why you hate the awp is that you’re used to a play-style that doesn’t have the sniper sitting around waiting in certain areas but has it move up with each opposing force (since most of the games you listed are more CTF and KoTH styles) and pick off anyone that tries to take on your frontal assault. You do not like just sitting around, you’re the type that HAS to run around and rush no matter what and thusly an AWP is a bad choice, meanwhile the shotgun is a perfect choice because you can jump and shoot with accuracy, turn a corner and instantly kill someone, and pick them off from a distance while still killing them in only one shot. I am not going to say “the awp is fun” because a person can get much enjoyment and fun with any gun. You don’t find the awp fun for your reasons and I don’t find the shotgun fun because I find the gun way too easy to kill people with and it causes a player to change the way they play to adjust to the “easier” style, in my opinion.
Also, I’ve played my share of FPS and have used a sniper in plenty of them and in plenty of the situations. Comparing the AWP to a Kar or Springfield is absurd as DoD, DoD:S, and other WWII shooters enable the user to be in prone and account for simulated breathing, hence forcing a player to crouch or be in prone to get a steady shot off.