I probably only just scrape into their concept demographic here but shouldn't we be?
I don't view increasing optimism as odd given that if all goes well, it won't be long before we're clearing out the last of the aged hubris running everything as it stands.
Then we'll be dealing with populations that are equally "socially liberal, technologically savvy and wildly optimistic" and finally able to take advantage of those facts to further our goals and those of humanity as a whole.
Is "economics be damned" and increasing optimism really that out there as an attitude when we're (in general, at least) more willing to accept alternative meanings of 'good' or 'happy' than any of our elders and this progress is nearing year by year? I wouldn't think so. And yes, I'm optimistic. Probably moreso every year...
(Edit: PS. I think this is more related to hacking than it seems. I think a lot of our tech savvy and liberal ideals are going to come into play and boost progress rates further. In particular imagine fields like biotech where barriers from aging ideals and prejudices will hopefully start to come down over those coming years)