VSCO Film for Adobe Lightroom CC, 6, 5 & 4: Selecting "Linear" from the Point Curve menu flattens the image, what's happening?

VSCO Film actually uses RGB curves for part of the contrast it does in conjunction with the custom profiles.

Selecting the Linear curve will effectively reduce contrast and break the film emulation and is therefore not recommended. If you’re after a toned down look, try the - version of the film you’re using.