Before I give my bit to the discussion let me ask you a question. Ever played a game and been on a roll only to have it stunted by something? Take age of empires for example, a game I'm sure the majority of you have played. Say you start the map and within 5 minutes the computer raids you to hell leaving you in a pretty pitiful state. Don't tell me you don't reload the same map and move to accommodate the very same attack so you can win and keep winning outright.
I bring this up because experienced gamers in their respective games are perfectionists. It's the same reason the first time you play a game is the best because the gamer is still exposed to unfamiliar circumstances and knows next to nothing about how the game 'works'. It's all about the experience. Play the same game a second time and words like 'unfair' and 'unbalanced' start to be thrown around and the gamer won't try to outsmart the opponent but instead the game.
The only difference here is that this same method doesn't work, because in PvP we're trying to outsmart each other in a game setting. So faced with this dilemma we - and I say we because we ALL do it - will try to get the best out of any situation by attempting to outsmart said scenario using our knowledge of the game and how it works.
What do we get from this? We all have our reasons. But I'm guessing a major one which I know personally drives my survival instinct is to know that the opponent hasn't made a tally mark out of me. Losing a fight is being reduced to that and many people understandably after all the work they have put into their characters aren't openly willing to roll with that.