I love Peerie Willie's style of playing, and while it has jazz roots the thing was that he obviously knew the tune repertoire well and adapted the style to fit. I have no problem with this approach. Where there is often an issue is where people who could well be experts in accompanying other genres assume that they can come in to a session without familaiarising themselves with the tunes, styles etc. attempt to apply a formula for backing tunes which works in the other idiom and assume it will work in the context of a session, often with dire results