It seems to me that there are two ways of judging either a creative talent, or a work of art. You can focus on brilliance (the creative heights) or you could scrutinize over whether it is perfect.
If you focus on perfection, a lack of flaws is most important. This would favor directors who spent a long time on their projects (Sergio Leone, Stanley Kubrick, Terrence Malick) which means that their average record will be much better.
I care more about brilliance, which means that I’ll pay more attention to heights than to the lows. This approach would favor prolific talents (John Ford, Alfred Hitchcock, etc.). I wouldn’t count the Ladykillers against the Coen Brothers, because life’s too short to see poorly received films, and True Grit was so awesome.
This approach can also apply to self-contained works. The best film I saw last year was Hugo. I thought it was a brilliant film, but not perfect. In comics, I’m astounded by the difference between the first issue of League of Extraordinary Gentlemen Volume 2, and the rest of the series. I would still recommend the trade. The distinction between perfection and brilliance can be important when trying to review stuff, as some will prize technical perfection above all else.
Atlas Comics had a Top 100 comic book artists list which sums up why I don’t like the idea of prizing perfection. They rank John Byrne at #69, and suggest that it would have been better had he just stopped.
For a core of fans who began reading comics in the late 70’s or early 80’s, John Byrne is a icon. His work on Iron Fist, Fantastic Four, and of course, X-Men cemented his reputation as a trendsetter and the superstar of his era. His early work featured some sharp drawing in the mold of Neal Adams and Jim Aparo, along with solid, well-constructed layouts that followed the classic template of the Marvel masters. He helped create or define characters such as Sabretooth, Wolverine, and Kitty Pride. The quality of his work has declined noticeably since his departure from Marvel in the mid-eighties, however. Stock poses; uninspired, repetitious layouts and sloppy finishes have helped drop him far down from his previously lofty position in the comics hierarchy.
I don’t like the implication that living longer and producing more work is a detriment to an artist’s ranking. John Byrne is one of the most prolific artists in comics, and I think that should count in his favor. By the perfection argument, James Dean is one of the best actors of all time, because he didn’t live long enough to give a bad performance. Charles Laughton is one of the best Directors, because he was only ever able to make one great movie.