Freddie at L'Hôte describes a process I went through about fifteen years ago. It's a result of experiencing qualitatively better things to which you once were quality-insensitive. Suddenly, you go back to something to which you used to be more quantity-sensitive -- beer in this case, but it could be wine or booze, or maybe some kind of food, or maybe a car -- and you find that your minimum quality threshold has risen above a point that what you used to enjoy is no longer good.
In this case, Freddie has discovered, as a lot of us have, that once you get a taste for Samuel Adams, Pete's Wicked, Sierra Nevada, and the like, it's very difficult to go back to something like Bud Light or MGD, much less a low-end product like Keystone or Mickey's Big Mouth.
Bad money may drive out good, but good product drives out bad.