Well,<p>1) if I understood correctly, the design of Angular has some inherent, and rather large, performance hits.<p>2) Google isn't dogfooding Angular save for one project. Facebook seem pretty serious about doing all new developement in React.<p>3) the specific kind of developement they're doing is similar to the one I have to do right now, viz. taking an established mostly static page and adding bits of highly interactive and dynamic behavior here and there. Google used Angular to reimplement the app from scratch. I can't afford that.<p>4) Angular, at what will probably the top of its popularity right now, just broke all interfaces and syntax and everything during the passage to 2.0, for reasons that were never fully explained (to me at least). Facebook won't be able to do that without breaking the proportionally large investment they had so far with React.js and incurring significant costs, which is nice and stable and comfortable. If the benefit/cost ratio of React 2.0 (or 1.0, I guess) is acceptable for Facebook, then it will probably be acceptable for me, too.<p>5) React interacts nicely with their Flow typechecker, which I think is, uh, the safest vector, right now, to foster the adoption of algebraic typing in the mainstream of programming. I won't typecheck my JS before the summer, probably, but still, this is philosophically fun.