I suppose various colors of dirt would be a sort of variety.
. The idea of views being continuous on I-10 west of Phoenix (for example) and rivaling the BRP is certainly a unique position.
That said, at the recent convention of the National Park Travelers Club, a representative of a support foundation for the Blue Ridge Parkway admitted that the VA section of the road is a bit underwhelming, at least further south than you were, actually.
Still, the BRP down in NC has some of the most spectacular views in the country, in my opinion (as do a few roads in the Southwest that come to mind, but saying that the Southwest is continuously scenic everywhere is a bit much
).
Then again, saying Skyline Drive was boring except for some nice views is also a little amusing. Anyone giving an NPS map even a cursory look would know that it is a ridge road with overlooks. Not sure what else one would expect. Entertainment? Comedy acts and bands at every stop? 
I think you misread me. I didn't mean to imply that every road in the Southwest is spectacular, or even scenic. The low desert in the southern parts of CA/AZ/NM tends to be less beautiful or interesting. But the roads that are spectacular are generally continuously spectacular, not just a short burst of spectacular every few miles. US-395 in the Owens Valley. Badwater Road in Death Valley. CA-120 and CA-108 over the mountains have long stretches of open views. US-89 and US-89A in northern AZ and southern UT. UT-12 and UT-24 and Monument Valley with their amazing rock formations.
I noticed this feeling while driving through Skyline: I felt slightly claustrophobic in the corridors of trees, and every now and then there was a respite that you could stretch out by stopping. Then back into the trees.
I've felt that even worse in the PacNW, where I lived for a while. You can drive along the old US-30 in the Gorge, right next to the Columbia River, and rarely see any of it due to 10 feet of trees and bushes between the road and the edge of the cliff.
I've lived out west from time to time and have had a couple of tree-hating friends from out there as well ("I can't see..."). Then again, my wife, who's from the Salt Lake Valley, was entranced by the eastern greenery (even just along the most boring stretches of the Thruway), and still enjoys how much life there is out here (while bemoaning some drawbacks of leaving the desert behind, like mud).
That said, although I agree with you on some of those drives compared to the BRP, it is still a sort of interesting position. Yep, not every road is spectacular out there, juat like not every road is spectacular out here.
And then there are those people that love driving through our forests in the fall due to the colors, lack of expansive views notwithstanding...