One thing that comes to mind is that a B&W sensor would require the use of coloured filters on the lens if you wanted to say, use a red, or green filter, etc. to modify contrast, tones, etc. whereas shooting in colour and converting later affords certain advantages and flexibility in this respect as you can get quite close to this in post processing with less bother in the field. I would think that this practical advantage would keep colour bayer sensors ahead in B&W photography. Anyone care to contest this?