IFNJ isnt just some random jumble of letters from a cat stepping on the keyboard. Its one of the 16 Myers-Brigg personality types, signified by introversion. And the INFJoe comic is meant for those guys and gals. As introverts, they want to be left alone to do their own thing, and away from all the rampant socialization. Naturally, that behavior rubs some people wrong.
The comic is drawn by a guy who is INFJ joe amid extroverts, sensors, thinkers, and perceivers, and still trying to come to terms with it on a daily basis. He started drawing with pen and paper, but switched to an iPad in 2013.