I think the terrain quality of the cited areas at Whistler/Blackcomb and Snowbird is vastly superior: longer fall line, more variations, much more snow. Plus those resorts have easily lift accessible expert terrain in addition. Hanging Valley and the Cirque (where the steeps are short and most of the run is a runout) are all Snowmass has in terms of expert terrain.
But to some degree I see the point. We shouldn't mark Snowmass down that much for "Lifts," when 90+% of the terrain is efficiently served. The real criticism of Snowmass is that it doesn't have all that much expert terrain for an area its size. Highlands has ~1/3 of Snowmass' acreage but far more expert terrain.
I thought the P2P at W/B was a crazy amount of $$$ to spend on a "scenic ride" lift, but last April I did find it useful. There were times when conditions suggested switching mountains and it was nice not having to go down to the bottom to do that.
The Peruvian chair is an effective safety valve for Snowbird tram lines. I never wait more than 2 trams during my timeshare week any more. Worst case scenario is you have to ski a run into Mineral Basin, then go up to Hidden Peak. Compare to Jackson, where tram lines can be huge because it takes 3 alternative chair lifts to get up only 3/4 of the vertical.