I think batsmen should walk if they know they have nicked it. But if we really want to make the umpires job easier, it is much more important for the bowler and the fielders not to pressurise the umpire if and when they KNOW the batsman to be not out. This is the bigger problem for the umpires today .
The fact that there are those , and so many it seems, who feel batsmen should not walk, is a sign of the times. After all we do have people who openly, at least in our part of the world, talk against paying taxes against voting for a candidate in an election because he is too good to be a successful politician, of justifying police and buraucratic corruption (and worse) on the grounds of their not getting adequate salaries and so on !!
The arguments offered about it evening out in the end was originally offered not to justify not walking but to shut up the cribbers who complained of mistakes in umpiring.
Mistakes even out in the sense that if there are mistakes against India today, there will be mistakes that will benefit them tomorrow. THIS DOES NOT MAKE THE MISTAKE RIGHT NOR DOES THIS MAKE ATTEMPT BY PLAYERS OR AUTHORITIES TO MINIMISE THE MISTAKES MISLPACED !!
No two mistakes can cancel each other out. They just add up !! Five mistakes against each team is ten mistakes and not zero.
Secondly, the impact of two mistakes can not be equated , even if they are in the same game.
Walking and not appealing unless you think you are right is what the players can do to help. The authorities have to think of what THEY can do in addition, technology or whatever.