“skiing is way, way, way steeper than mountain biking. Going down a red ski run on an MTB is pant-wettingly steep”
Steep yes, but not as you describe imo. Have used ski runs (in summer) to link up trails and not as bad as you make out
In winter with a bit of icing going on I can see would be a completely different. Perhaps just an exersize in brake control, or lack of
re: DH skiing, I cant see the lifts being setup for bike use in winter. chairlifts/bubbles having had the bike racks removed, lift attendants (at busy periods) perhaps having enough to do monitoring ski-iers/snowboarders getting on/off lifts. The big ‘twin-box’ lifts (name escaping me) a bvike would take too much space up. Ski-resort/lift operator wanting to keep them full of skiers/snowboarders
Also demand?
How many people even know of ‘fatbikes’?
How many people would actually be interested in mincing your way down a ski-run on one