This opinion is from a neophyte when it comes to feeding raw feeding.
I chose to go raw about six weeks ago because I was tired of feeding Ritz low quality canned seafood flavored food (the only flavor she would eat) and her always being hungry. In desperation I started feeding her commercial raw. She loved it from the first bite (we're still working on amounts and hunger issues).
Then I ventured into frankenprey. I got over my squeamishness when handling jello-like raw liver and kidney because of how much I saw Ritz liked eating it and how much energy she had. I liked (well kind of) hearing Ritz crunching bones, chewing meat/poultry like she was meant to do. I've also given her a few crickets to play with and eat. I am now back on feeding commercial raw until I understand the ratios better (80/10/5/5).
But whole prey, my own personal comfort level isn't there yet. Although I like, really like, the fact that I wouldn't have to guess at the proportions for whole prey, so that possibility is still in the back of my mind. I've thought about buying some frozen pinkies and small mice. Thinking about it still.
As for the reason whole prey hasn't caught on: like a lot of the other posters said, comfort level and cuteness factor. What that individual level is, isn't a bad/good thing, it just is. Today, canned wet food (yesterday, dry kibble); tomorrow, commercial raw. Or, always canned wet food.