If people are doing good in the business that is great, but posting that link without context does seem like kind of a passive-aggressive dig IMO, especially after what was said earlier in this thread. It might or might not be intended that way, but that is just how it comes off to me.
With that said, not every business is for everyone. There are many people more intelligent than me, but that doesn't mean they would be better in this field. There are many people less intelligent who are far more successful in the field.
It is just a fact of life that hard work doesn't always yield results unfortunately. There are endless other factors in play some within your control and many outside your control.
If what you are doing is not working, try to figure out why, and come up with a better plan. There is no "failure" if you learn and grow.
One of my favorite quotes is by Thomas Edison -
In response to a question about his missteps, Edison once said, “I have not failed 10,000 times—I’ve successfully found 10,000 ways that will not work.”