This is a _completely_ different sort of recovery though. The Shuttle SRBs just fell into the ocean under parachutes. The F9 first stage will be 'landing' under its own power (after decelerating itself to reduce aerodynamic stresses).
Also, the SRBs were not "rapidly reusable", they were not simply refueled or merely refurbished. They went in sections back to Utah for essentially re-manufacturing. It was more expensive to reuse the SRBs than to buy new ones, but the decision was made to reuse because of prestige.
I suspect it had less to do with prestige than jobs. A large chunk of the initial SRB cost was raw materials, more of the refurbishing costs was manpower. Congress critters dislike direct welfare but but put a fig leaf on it an call it a middle class job and there practically in love.
