They should know that the blues scales were originated by the slaves that were not allowed to converse on the plantation. So they sang their wretched experinces to each other, thus the formation of the blues scales to convey this. That's the essence of it all.
Actually, from what I hear in the music, (and of course there are exceptions) blues bass is really much more roots fifths and major thirds and sixths and possibly a flat seven in a walking context. Leave the blue notes to the guitar and blues harp players.