I did a search ("Leading Hotels of the World" - not helpful, as I got posts with "the" and "leading" and hotels" etc.) but couldn't find anything.

It looks like, from lhw.com, that Mandarin Oriental, Ritz, Peninsula, Four Seasons, etc. - all have pulled out. When did this happen? Why? I'm just curious, as I used to like LHW as a gauge before I stayed somewhere, and it's surprising that none of them seem to participate at all anymore.