Soft brake pedal

Brakes go to floor. Have to pump them to stop for
the last few months. Did rotors and pads all the
way around. Replaced both calipers up front as
boots around piston we're cracked and worn
through. I bled brakes from farthest to closest all
the way around several times. Still soft pedal. I'm
thinking master cylinder is bad since the problem
originated before I cracked lines to do calipers. I
also used bottle and tubing and replaced fluid in
system. It's nice and clean now but no pedal still.