I did say that day was their best day they ever had which was Christmas last year where they were selling 400+ items a second.
No you didn't, you said "To be fair that is a good day but still." I hardly think "best day in the history of the company, during a holiday" is the equivalent of just "a good day", as the later implies it's a lot more common than simply a unique day in history.
2014 has seen about $4.2B in non-electronic book sales for Amazon. 2000 saw about $2.77B in non-electronic book sales for Amazon. That's only a 66% increase in 14 years, and not the massive jump you keep implying by quoting things like total Amazon customers or total Amazon revenue or total Amazon product sales in a day (none of which had anything to do with books in particular).
Now that I have compared the 2000 book sales to the 2014 book sales, and we see they are not even double at this point (for books), do you see what I am getting at when I say 2000 was a good year for Amazon's book sales and therefore number of reviews for a popular book from 2000 shouldn't be simply dismissed due to the year? Sure, their book sales have increased 66% in 14 years, but that has also had 14 years of reviews (they did not all happen in the first month). It's noteworthy that 5e has this many good reviews, this quickly.