Ugly? Death Valley is part of the Mojave, and it’s one of the most beautiful deserts around!
The exception proves the rule. DV is beautiful because of its extreme geography (11-14k foot verticality). The Mojave/GB lacks the flora/fauna of the Sonora (eg saguaro), the color of the Colorado, and the elevation of the Chihuahuan.
The worst roads trips in the US are the I-10 from Palm Springs to Phoenix, the I-80 from Reno to SLC, and the I-40 from LA to Vegas. I've done them all (on many different occasions); the Mojave is a colorless, lifeless, drab, boring & depressing desert.