Well, let's take a look at the Super Bowl commercial as an example where the bloke used Google to find a mate, find a restaurant, shop for flowers, find a ring, etc.
These were all positive experiences that followed from positive searches. Nothing to do with bounce rate, time on site, keyword density, etc. all factors ON the site. The positive or successful experience was determined by the search that follows.
Perhaps if enough people search for "best engagement ring" after visiting a dating site, that would deem that site a great user experience (vs. "how to get rid of a stalker"). LOL.