Uphill sections often have a time cutoff, so you can't walk your way up... you have to make it up there in a reasonable amount of time, and if you don't I've seen time penalties too.when they start timing the uphills too, I'll pay attention. You can still do "stages" but now it matters who gets to the top first too.
Regardless, I see it being a decent thing for places that don't have lift access....but most places that don't have lift access around here don't have good trails either.