I’m not sure if this is something that happens to everyone, but as a designer, I can say that having to interact with the horribly designed is the biggest turnoff. (I almost initiated a plan to no longer eat at a restaurant with Comic Sans on the menu… though I quickly realized I would go hungry very quickly!) Dustin Curtis, a user interfaces designer, was so offended by American Airline’s website that he took upon himself to show them how it should be done.
AND, the response from the AA.com UX architect.
Via Surfstation