Yeah I would have said that same thing a month ago, but I just got a midi win controller and have been creating backing tracks for some of my favorite flute peace's that I played when I was playing the flute way back when.
I still mostly use BIAb for original songs though.

To be honest if I actually thought I had a for sure hit on my hands I'd send my song to a pro recording studio and have them do the arrangement and vocals.
Don't get me wrong I think BIAb's great, but I sure ain't no singer and as good is BIAB is I think most of the time a pro studio would do a better job.

Tim