In reply to philhilo:
You're right that all strands of climbing have rules. It's the nature of sport to define and respect limits as to what's permissible in a given discipline. My impression is that even though all of these imposed limits exist for good reasons, some are much more contrived, less intuitive, than others. Just because all sports are contrived to some degree, doesn't mean that all sports are contrived to the same degree.
The most natural and intuitive activities, to my mind, are those that kids will play without even thinking they're doing sport. Running, jumping, throwing, climbing, swimming, etc. Even though these have all developed into sports with strict rules, you don't need to know the rules to enjoy the sport in its most basic form. Any rules are really there just to preserve the fundamental nature of the activity. So, for example, you can't wear skates in a running race, you all need to be throwing the same type of object or jumping from the same line.
Climbing, at its simplest, is one of the most natural and intuitive sporting activities. But as with any sport, there will always be ways to improve performances by sacrificing some of this inherent simplicity. Left unregulated, runners would be using springy shoes, throwers would be using slingshots, and swimmers fins. The equivalent in rock climbing is the use of artificial hooks instead of handholds. Within defined limits runners can still use cushioned or spiked shoes, swimmers can wear shiny suits and climbers can wear rubber-soled shoes, none of which change the sport's fundamental simplicity. In essence, any rules are there just to maintain the nature of the activity, not to define it.
Climbing is in some ways a special case, in that reaching the highest and most inaccessible peaks has simultaneously presented a very different objective, with very different means. In Victorian times up until quite recently, the only way to reach many peaks was to use every technological advantage possible. That includes bottled oxygen and fixed ropes, of course, but also it was the driving force behind aid climbing. As much as reaching the summit of the Matterhorn or of Everest for the first time was a tale of human skill, it also was a triumph of technology. Even though aid techniques weren't a natural or intuitive class of human movement, they were a necessary means to the end of scaling a particular peak or a particular face. Ice climbing too is a technology-driven activity - for very good reason and far better for it.
Climbing therefore has evolved simultaneously both as an expression of natural human movement (like running or swimming) and also as a technology-assisted endeavour (like ballooning, archery or sailing). And this is where the confusion lies.
Using sticky rubber or chalk is the equivalent of using running spikes - they might help a little but they don't change the activity at its most basic level. Using hardware to physically assist climbing progress would be more like pole vaulting is to high jump - not necessarily less enjoyable but definitely very different and less fundamentally child-like in nature.
Dry tooling I see as an awkward hybrid between the two competing influences of the unassisted human performance of free climbing and the technologically assisted progress of pure aid climbing, and that is why I think I find it less compelling personally. Others may really like that combination.
Using technology to make an activity safe (or safer) is a further complication and one that also detracts in many ways from the simplicity and naturalness of climbing. But of course it does so for good reasons. Both sport and trad climbing have evolved to maintain a strict rejection of any technological assistance in actually making upward progress, and in doing so they've managed to retain what I see as the purity of physical climbing, even if they are far less 'natural' or more contrived in the way they're protected.
Well I started out trying to explain why I think dry tooling is more contrived than sport, and I ended up thinking and writing more than I expected. Few things in life are simple, eh?