I don't think most people articulate why they dismiss gearboxes very well, or at all haha. For me, I'm not too interested in them for a couple of reasons. Firstly, I don't have the issues with derailleurs that others seem to have, I don't smash them or snag them on rocks, and I race DH and enduro in Utah and Colorado so there are plenty of opportunities for me to do so. Secondly, I like mechanical drivetrains and don't like grip shifts. Unless I have missed something, all mechanical Gear boxes have to use a grip shift to pull cables...