Sorry, this was too terse. I'm inclined not to use Knockout because I find the branding unappealing and a bit too visually intense. I think backbone.js[1] has been so successful in no small part because the website is excellent. Very simple, easy on the eyes, explains itself, and gets right to the point: documentation. Angular's too[2].
Choosing a product because you liked the commercial, choosing a book because you like the cover, choosing a bottle of wine because you like the label, choosing a computer because you like the design, choosing clothes because you think they look good is a bit... Superficial, no?
When you choose a technology with a bad website, you have to actually look at that website for hours and hours reading the documentation. This can be incredibly frustrating for people who are sensitive to such things.
But more importantly, there's a subtle biasing. People usually do not make rational decisions about technology. The design of the website is a more significant factor than you might think, at least in my experience of watching people make such decisions. If it wasn't, then why would anybody bother to make a good website?
