The article is about choosing a business idea where technical scale isn't important. Twitter would fall under a "media play" which is what the author is telling the reader not to do. They aren't saying "try to build twitter but skimp on the tech" they're saying "don't try to build twitter, build something where people pay you money to use it and you'll be raking in millions in profit by the time technical scaling is an issue". Terrible example imo.