Personally, I believe that SF embraces multitudes. It is not a genre that can live with constrictions or presciptions. SF is literature that needs to be free. It is dynamic, creative, and powerful, and IMHO still the best way to tell stories about what it means to be human. The only thing that the mundane SF adherents seem to want to do differently from the rest of us is to not rely on ideas that aren't proven via peer-reviewed scientific methodology. Okay, that's sensible and a great thing to teach new writers, but it doesn't feel like a new direction for the genre. Maybe I just don't get it (and I'm currently discussing this with blzblack).
If someone writes something that deals with the effects of change on the human condition and extrapolates into the past, future, or distant places, they're writing SF, pure and simple. You can subdivide it into subgenres, but no one subgenre has the right to claim supremacy over the others. SF readers and writers, especially, should know better than to condemn another neighborhood in the ghetto we all share and love.
EDIT: PS: The word "mundane" has been long denegrated by SFnal folks. It usually means the non-SF people who are incapable of viewing the universe outside of their little life's confines. Many of them fear and loathe SF. So what a strange thing to want to call your approach to SF!