I'm well aware that braking takes some share of the available traction, but I think that worry is overblown. We just aren't riding the limits of traction often enough for still having some brake on during turn in to be a concern - certainly this mythical inexperienced descender we're discussing won't be pushing the limits that hard. If anything, it's safer as it gives much better control of speed through turns on a descent. Releasing the brakes fully during a downhill corner is relinquishing control of acceleration due to gravity. I don't buy the argument that this is somehow better and safer for an inexperienced rider than riding the brakes through the apex of the turn. Very few, possibly none of the downhill crashes that I've seen on dry roads resulted from a loss of traction. Anyway, that's my take on it.