The SFC is a bunch of wacko's and they cannot speak for the free software "movement." Last I heard about them, they were mad about somebody suing for a GPL violation.
https://sfconservancy.org/projects/current/
Half of their staff has worked for the FSF in the past. More than one of them has given a keynote at the FSF's anual conference. These folks are tightly integrated into the bits of the free software movement most closely associated with RMS; the fact that they've come out and said this is a big deal.