Because it's been years in the works, it's finally about ready, and Racket only now is in everyone's mouths? Guile is now also able to run other languages as well, like Javascript, or at least so their maintainers claim.
Besides, I know that among users of fringe languages like us (you too are, I presume) this is a bit of a taboo question... but who uses Racket so much as for it to make a difference here?
Racket (Formally PLT Scheme) has been the dominant scheme for serious use for years. It's not "the n3w hawtness" by any means, but the established leader.
Besides, I know that among users of fringe languages like us (you too are, I presume) this is a bit of a taboo question... but who uses Racket so much as for it to make a difference here?