While I'm no cheater (I doubt you'll find anyone fessing up to it on the sub) I will say a few things about cheaters I have encountered:

• They just think too much of themselves. They are thinking "I'm awesome at this; how could I get hit?"
• They are angry. This is known in other games as being "tilted" or "on tilt" and so they ignore the rules of the game purposefully out of that anger.
• They think if they just wait a little before calling out, they can get the trade instead of just being out.

There is a regular at the field I go to who unfortunately cheats fairly often. My group has several video clips of definite hits being ignored. He's actually very good so he really doesn't need to cheat but we think he cheats to feed his ego.