It's ironic ... The NIMBY's didn't want the BART to go through their neighborhoods, but having two stops in Mission is part of why it's so attractive now.
So type A NIMBYs were "right" in that they didn't want BART to go through their neighborhood because it would case the neighborhood to change, and lo and behold it did. Type B NIMBYs were "wrong" if they argued against BART because it had a positive effect on their home values.