>Is it your contention that Dylan is really a great singer and he's created this voice that by the most generous accounts is not 'traditionally good' on purpose?

Yeah, something like that. Maybe not a great singer, but hearing him do some things, it's clear that he could've sounded quite different than he did most of the time if he'd wanted. Certainly a very good singer, in spite of not having a great voice. Keeping in mind that there's a difference, and that I'll always consider a singer to be very good if they're able to do interesting things & convey emotion well when they're working with a less-than-average instrument. Ironically, it's on what these days is probably Dylan's most played song--Lay Lady Lay--that it's obvious that he had a range & a timbre far beyond what was displayed on much of the remainder of his best-known work.

If you or anyone else prefers Marley, great. But even if I did I don't think I could vote against Dylan, taking into account his importance & influence. Marley's another guy who came along after Dylan who performed original material. Again, when it comes to pop music, practically nobody did this prior to Dylan. He was the first guy that people took seriously who happened to write his own songs. Obviously someone would've come along to blaze that trail if he hadn't, but he was the guy. By the time Marley & the Wailers formed he'd already opened that door--and if he hadn't it's even possible that at that point in time a potential career performing original material may not have even been a serious proposition.