I was being a bit facetious, to be honest. But the author could have let the space be blanco and truly inobtrusive. In a sense buying a can of spray paint and illegally (I assume) defacing a surface is an investment in your message being read by multiple people.

I mean I agree with the general sentiment of it, but to follow your adblocker methaphor your ads would be replaced by the opinion of a random dude, which is obtrusive too, imho.