In my case, judicious application of AdBlock and NoScript make this a complete non-issue. I'm far more interested in standards compliancy and security.
Reality suggests exactly the opposite. Adblock, Noscript, and whatever other browser plugins you use, in addition to most of the UI code on web pages, is written in JavaScript. Browser speed, and particularly JS execution speed, does matter. In fact, since you are running these applications, which run Javascript to customize your viewing experience, you probably depend on speed more than you think.
You sound like you haven't been in school for awhile, so let me remind you of something: HIGH SCHOOLERS ARE IDIOTS. I know, I was there 3 years ago. As to the "innate ability" argument, I convinced 3 of my friends (all took AP calc, one is a math major at W&M) to take AP Comp Sci with me, and none of them did well. They just didn't "get it". The asian kid who is now majoring in math did the worst. It really seems that you don't have the slightest clue of what you're talking about. NOT everyone can learn CS if they want to.
"And remember: Evil will always prevail, because Good is dumb." -- Spaceballs