It can also cause Google to ban sites from Adsense.

Google will ban a site from hosting Adsense ads if Google believes that the site's operators are generating fake clicks. The way they detect this is a trade secret, but many sites have gotten arbitrarily banned after users seemingly clicked ads artificially in a misguided attempt to help the site.

This extension will no doubt be used by a certain subset of users. Those same users may use some sites in a disproportionate number, that could result in people's favorite sites getting banned and losing the ad revenue that keeps the lights on.

I don't actually think this extension is "bad" or "wrong" just might have unintended side effects.