We've come a long way in those 266 years: global population 10x'd, meanwhile the share of the population living in extreme poverty went from over 80% to nearly 8%, so not all optimism was misguided. Also there's a lot of room between despair and a Panglossian caricature, and I don't think acknowledging that a lot of good has happened in the past (and not necessarily suggesting it was all inevitable or automatic) rises to that caricature.