Rob, you could take that attitude and say why bother doing anything if you'll never be as successful as x, y or z.
Sure that's not an average mini site, it is a
tool/calculator type of mini site hence it has added viral value, that doesn't negate the value of taking a domain, adding unique content and trying to more than pay for itself, with a good domain and an idea you can spend a little longer and get a site like that for very little outlay and a good return or stick with an info based site and more modest return.