He was champ for a good long time and prove his skills against very solid opposition. I have him at 8 or so.
He probably doesn't merit being in the top 10. But, his wins late in his career at other weights have helped make his career look a lot more impressive than it actually was. Certainly there are a few dozen men at 160 who are likely to have beaten him. His fight against RJJ was not remotely close, and Bernard lost twice (admittedly close fights, but twice) to Jermain Taylor. I doubt too many people have Jermaine Taylor in their list of top 100 middleweights. A prime James Toney would have beaten Bernard at his own game and made him look silly. A number of skilled boxers from the past (Robinson, Hagler, Monzon, Flowers, Leonard, Nunn, McCallum, Griffith, Giardello, etc.) would have out boxed him, and a number of pressure fighters (Greb, Fullmer, Basilio, Zale, LaMatta, Cerdan) would have outworked him.
You may have a point there. His longevity has been so awesome that I may be thinking of fights that weren't actually MW