I've been using the road twice a day for years, although I go from home in Shirley to work in Hythe so I avoid the worst of the jams.
The problem as I see it is not the road but a minority of the bikers. Some of them go at such high speed when compared with the rest of the traffic that it's not surprising that they come to grief. It only needs one of the heavy trucks to wander slightly towards the middle of the road as they are being overtaken and these guys would get swatted into the undergrowth.
I keep a eye on the mirror and move over for bikes but some of them come up behind you so quickly that often, you don't have time to react.