In reply to Bruce Hooker:
I've got 56 years of climbing experience. I started with soft iron pitons, progressed to chromemolly pitons, acquired and made first ascents with a set of fifteen nuts from Joe Brown in (I think) 1968, and have followed and eventually adopted all the improvements and inventions since then.
Just a few days ago, I did a moderate route (5.7 or 5.8, VS or maybe HVS?) which, however, would have been a solo without modern gear. All the protection was either opposed tiny wired stoppers, microcams (blue Alien, grey C3), and Ballnuts, with two 1/2" cams for the "big" pieces. The placements were primarily in shallow and slightly flared horizontal cracks---not even a prayer of getting a 1970's nut to hold up a carabiner, much less hold a fall, and I say that as someone who has climbed extensively with 1970's gear and am very expert in using it.
This is just a single example of the fact that, at least here in the U.S., there are thousands of climbs most climbers wouldn't want to even get off the ground on with a 1970 nut collection. The protection revolution has been absolutely enormous, a true paradigm shift. It has made death routes into trade routes, hard pumpy climbs far easier to lead, runout cimbs well-protected, has enabled a generation or two of climbers to casually approach routes that were once very serious, and has opened entire areas, like Indian Creek, to extensive development, where almost none would have been possible with 1970's equipment. The idea that these sea-changes are a matter of small details simply misunderstands what has happened generally in the last forty years and can only come, I imagine, from a very limited rock-perspective.
As for chalk, it is clear that, no matter what the proportions look like here, an overwhelming majority of climbers find it useful and effective. I agree that it is terribly overdone, and subject to reflexive use, and hate the "connect the dots" effect that it has. The climb I mentioned above had no chalk on it, and deciding which collection of small insecure holds to use was one of the primary challenges, with the possibility that a wrong choice might add multiple grades to the difficulty and even lead to a dead end. Having a line of chalked holds to follow would have avoided much up and down and side-to-side exploration and would have made the route an entirely different and much easier and less stressful undertaking. I did the climb on a fairly typical Eastern summer day with temperatures near 90 and very high humidity. I had sweat pouring down my face and afterwards was able to wring out my sweatband like a saturated wet washrag. Chalk was, for me, an essential aid.
Although it seems unlikely to ever catch on in an important way, the use of a chalk sock enormously decreases the adverse visual impacts of chalk while providing almost all of the benefits. Looking up at the route after I led it, you couldn't make out any of the handholds, for example, because the chalk sock deposits just a thin layer and little of that transfers to the rock.
There is also an aspect about chalk that hasn't been mentioned: it mitigates the transfer of hand oils and grease to the rock. If no one used chalk on popular routes, I suspect some of them would become horribly greasy, worse as far as gripping than the overchalked holds encountered now.
Pouf is another matter. I don't know what it does or doesn't do on the hands, it always made mine feel slipperier whenever I tried it, but its primary negative effect is to transfer black rubber stains from shoes to footholds. These ugly stains seem to be quite permanent, and are a feature of many boulder problems in Fontainbleau from the days when climbers regularly pouf-ed their shoes before starting up a problem.