Its not so much about not wanting to see the ads, is about the app using phone features like GPS which drain the battery.
Even if the ads don't show up, that doesn't mean that the app isn't still using these extra permissions and draining the battery. I don't have a problem seeing ads, I have a problem with the fact that seeing ads often is tied to apps draining excessive battery life. So I'd like to be able to disable an app's ability to use GPS to find my location (and thus save battery life). Make sense?