Even if we ignore the social impact of marketing, it's pretty sad when people who work in communications believe that they are only required to be original once a year.
The original carnival days like "Feast of Fools" [0] were an outlet for subversive undercurrents in the otherwise immobile medieval societies. You could be Pope for a day, but you were still a beggar for the rest of your life and nothing would change that.
Marketers who play April Fools unwittingly paint themselves as the beggar in this scenario. It's like they're broadcasting a message: "I feel like my work has no meaning in this world, but at least today I get to pretend that I'm the one making the news."