> If you look at "top 100" blogs in year n, I imagine that many of them will be dead in year n + 5 simply because people move on.
This is a far more dubious hypothetical. I imagine that the top 100 of anything (that a lot of people do) that brings in income or fame will still be there in 5 years. They're the most successful, most profitable of the bunch. How many of the top 100 companies in terms of revenue do you imagine will disappear in 5 years? I'd guess around 0.0%.
"People move on" is a meaningless statement. Why were there so many colon cancer deaths over the past 5 years? Well, people move on. Why do people move on?
> Also note that this specifically focuses on blogs designed to make money
i.e. blogging, which once brought in money, doesn't seem to as much anymore. Why?
If we use the S&P 500 as a proxy for the top 500 companies, I would guess that a lot more than 0% will be gone by the end of 5 years.
It's hard to find non-paywalled sources for business analysis, but from what I can find it'd be about 20%.
> I imagine that the top 100 of anything (that a lot of people do) that brings in income or fame will still be there in 5 years.
This sort of blanket assumption is exactly what the parent is arguing against. The mortality rate of top-n things is relatively easy to measure, and should be baselined first. Then we can compare recent performance vs historical performance, and actually say if something has changed. There's no need to start with the assumption "not much changes over 5 years" -- it can be measured instead.