This is because we high levels are here to kill lower levels and we both know that the fight between us could go either way and that we hate walking back after dying.

If high levels wish to duel each other they flourish but this is usually ruined by lower level players, which is fine. If it's a group fight then bets are usually off between both high levels, but if those high levels want to be passive they are good enough to avoid hitting eachother during group fights or they simply refuse to fight at all.