People aren't using Adblock to conserve resources. They're using it to block ads and most are willing to take a performance hit to do so.
It is a sad reflection on the state of advertisement, but lacking any viable alternatives, using an adblocker (and NoScript) is pretty much non-negotiable to me. I am always apalled when I have to use a browser without an ad blocker installed.
It is not that I mind the ads in general, but too often, they are seriously distracting, and advertisers seem happy to go totally overboard. Imagine walking down the street and looking at blinking, flashing billboards. Imagine turning on your car and being greeted by an ad before the engine actually gets going. If ads outside the Internet were as annoying as they are online, we probably would have riots. (And that is ignoring the malware.)