My husband and I have done this trip 3 times before (the last time was 20 years ago).
I realize times have changed and that's where we need to adapt. We enjoy spending time in the city. We have plenty of activities planned for our days in SF, LA and Las Vegas. And no... we are not spending time in the casino's. We probably are a little less into nature than other travellers who frequent this part of the USA. Scenic drives with comfortable (m)hotels and decent places to eat are all we need to have a wonderful and memorable vacation.
Does that mean we are insane? Maybe. But we are not complaining...