Tone is totally subjective, so I'm guessing Nick Valensi uses a Hot Rod Deville because he likes how they sound and he is familiar with them.
People think I'm weird for liking old Magnatones, Supros and Silvertones, but I think they sound great. We all have our own ideas of what we want to sound like. I think a lot of the ideals of 'tone' are myths, smoothness, upper mids, bloom, etc. Most people learn these from listening to guitar nerds, who lets face it have no idea about music in general and more knowledge of Claptons amp settings with Cream. I was even told once by a sound engineer I'll never sound decent with a Tele and a Fender amp and that I should just get myself a Les Paul and Marshall. As ludicrous as that sounds, that was the general consensus everyone around me held.
Also remember hardly anyone in a crowd or listening to a record actually gives a toss. How many times have you seen a band where the crowd is wetting themselves even though you can't hear the bassist, the drummer sounds like a toddler kicking tin-pans down the stairs and the guitarist has so much distortion going you'd be hard pressed to work out what notes they were playing. Well in my experience virtually every gig I go too. Big bands like the Strokes won't have their success curbed by having average tones because they are just another indie-pop band, where hairstyle and attitude will get them where they want to be.