WOW!I think a lot of it is us as fish keepers wanting the sense of accomplishment. Whether your position is Goldfish are high or low maintenance, guess what? 9 times out of 10, you'll have a 'happy' hungry goldfish regardless of your approach. You almost can't kill these fish. So that makes them an awesome starter fish. Just like anything else you do, people sometimes like to show their progression in their hobbies. We know how much thought you can put put into making a goldfish happy, just as much as lots of other fish, but for some, the wow factor just isn't there, so people move on.
And that suffocating "look mommy, he's talking to me!" intro to the hobby really wins the kids over too!