Wasn't the 'B' a little less expensive than the 'C'?

That might have factored into it a bit, plus the 'B' gives the organist a bit better sight-line to make eye contact with other musicians and the congregation, whereas the 'C' was more for the traditional 'turn your back to the congregation' church organist, I think...
_________________________
An arranger is just a tool. What matters is what you build with it..!