Sure, someone who thinks that if he creates a new facebook widget he'll retire -- that guy may need to hear this. But wait, does he? He'll figure out the problem with that soon enough.
The rest of us ... do we need some smug guy telling us that the Plenty of Fish guy was just really lucky? I've read the Plenty of Fish story, and it sounded like there was a lot more than luck involved -- and that luck was the smallest component. Oh, and I've worked at other startups and know people who are quite rich because of them. It didn't take them five years and only luck. It took the right idea at the right time, and in some cases, multiple tries.
No, successful, wealth-generating sites aren't born every day.
But it's more possible to create one than this guy seems to think.