According to Eric Ripert, Bourdain had been "in a dark mood these past couple of days." Could be a coincidence, but that matches up with the timeline of the Daily Mail
posting photos of Bourdain's girlfriend, Asia Argento, looking very friendly with a young reporter on Tuesday.
If that's what drove him to it, I can at least take some comfort in the possibility that he did enjoy his life, but that he couldn't take having another relationship fall apart.