I think walking or not is different. The umpire is there to make that decision and I don't see a problem with players leaving it up to him in competitive cricket. Fair play to those that do walk, but imho it's harsh to tar those that don't with the same brush as cheats.I would argue that if the player never walks it is calculated and pre-meditated, and if they are wrongly given not out, it affects every ball thereafter
DRS should balance it out if a non-walker stands his ground anyway these days. It won't always admittedly, but the same is true if he's wrongly given out.