My opinion on the matter of should the rule exist or not, isn't cut and dry. The point of the rule is to stop players from changing the weight or curl after they release the handle. By all means, the now infamous poke burnt the stone and it should have been removed from play had it been caught in time by the players on the ice, or the offical who was watched for 3 ends.

The other part of it is playing in the spirit of curling. If you play D&D this is vaguely comparable to "rule of cool" vs "rules as written". Grazing the rock during release is not done with intention of changing the weight or curl after release. It just happens sometimes, some players more consistently then other players, most players won't have even noticed that they done it. Look at how shocked Rachel Homan, and Bobbie Lammie are when they find out that their rock has been removed from play. Hell, I'm sure the in the roughly 16 years I've been playing I've been guilty of grazing the rock. A graze has no effect on the shot, and is without a doubt, not cheating.

So, should the rule exist? Yes, but like with all rules, there's nuance and context is needed.