It seems perfectly reasonable for someone who created an alternative to explain why they did it. Maybe the page should be titled "Why sqlite dev(s) created Fossil", but it certainly doesn't come across as disingenuous to me.
Because they don't want to come across as pushing their own product, I guess. I saw a recorded talk by the Fossil creator a couple of days ago where he talked specifically about git and how it could be improved. He was extremely reluctant to name Fossil explicitly, although he stated upfront that he has developed similar software.
