Carl becomes something you understand more as you age. Some people kind of suck and make terrible decisions. He blows all his money on stupid shit he doesn't need, fills the emotional void with people he either has to pay to be there or have no other option, has basically given up at whatever would actually make him happy, and has the kind of lifestyle you find a lot of desperate, stupid older men fall into to varying degrees.
Which makes shit like those weird commercials really questionable. Carl is the kind of guy who would eat KFC at every meal, but why does KFC want to use him to promote their brand?