I'm often told that.

Truthfully, I believe most people don't really complain while on-site even when things go pretty awry...instead following what I consider to be a passive-aggressive approach, not saying a thing there and then complaining about it afterward on blogs/reviews and to everyone they can. It's impossible for a hotel to recover when you don't share that something is wrong in the first place.

I actually think that's why air con can be so hit or miss at so many (even luxury) hotels--most people don't seem to really care about it being a little warm, so hotels mistakenly believe the illusion that their air con works well. Then I come along and educate them.

Most people also don't ask for something specific and/or appropriate when things go wrong. But the hotels/managers that don't need you to do that and still recover with aplomb are the stars.