A320 FLT CREW DEPARTING FROM SNA EXPRESSED CONCERN REGARDING ATC'S RUNWAY USE DECISION GIVEN THE MULTIPLE WIND SHEAR REPORTS BY DEPARTURE AIRCRAFT.

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MULTIPLE RPTS OF WINDSHEAR ON THE DEP. RPTS OF LOSS OF AIRSPD OF UP TO 35 KTS RPTED BACK TO TWR. I REJECTED INITIAL TKOF CLRNC AND ELECTED TO LISTEN TO THE NEXT TKOF RPTS. FINALLY; TWR CLRED AN ACR X; A320; FOR TKOF AND I ASKED THE CREW TO GIVE A PIREP TO US AS WE WERE CLRED INTO POS. THE ACR X CREW RPTED WINDSHEAR BUT NO LOSS OF AIRSPD. WITH THAT RPT WE DECIDED TO ACCEPT THE TKOF CLRNC. HOWEVER; WE ELECTED TO KEEP AN ADDITIONAL 20 KTS OF SPD RATHER THAN MAINTAIN V2 ON THE DEP WITH THE NOSE HIGH ATTITUDE OF APPROX 22 DEGS FOR NOISE ABATEMENT. ADDITIONALLY; WE BRIEFED NOT COMING BACK TO CLB EPR UNTIL WE WERE COMFORTABLE ABOUT THE POSSIBILITY OF WINDSHEAR. AFTER TKOF CLBING THROUGH APPROX 500 FT AGL; WE GOT A FAC GENERATED 'WINDSHEAR' ALERT WITH AN APPROX LOSS OF 30 KTS. IT WAS A FAIRLY BRIEF EVENT BUT CERTAINLY ONE THAT IN RETROSPECT I SHOULD HAVE GONE WITH MY INITIAL CALL TO NOT ACCEPT THE TKOF CLRNC. IT WAS THE PIREP OF NO LOSS OF AIRSPD THAT CAUSED ME TO REVERSE MY ORIGINAL DECISION. MY FO RPTED A LOSS OF AIRSPD TO SNA TWR/ATC AND RECOMMENDATION TO CHANGE THE RWY DIRECTION. I CALLED SNA TWR AFTER ARR AT ZZZ AND SPOKE TO THE TWR SUPVR TO EXPRESS MY EXTREME CONCERN OVER WHAT SEEMED TO BE A PROACTIVE APCH TO SUCH A CATASTROPHIC SCENARIO. I ASKED THEM IF THEY CHANGED THE RWY AND THE SUPVR SAID THAT THEY ARE RESTR BASED ON HAVING A 5 KT TAILWIND. I SAID THAT PUTS THEM IN A PREDICAMENT; AS THEY JUST CONTINUED TO LAUNCH. I ASKED THE SUPVR IF ANY DEP RPTED WINDSHEAR AFTER US; AND AT THAT POINT THE ATC REP APPEARED TO BEGIN TO MARGINALIZE MY CONCERN AND LITTLE PROACTIVELY TOWARDS SUCH A DANGEROUS SCENARIO. I IMMEDIATELY BROUGHT THIS TO THE ATTN OF FLT OPS PERSONNEL AS I FELT THAT THIS LACK OF CONCERN BY ATC COMBINED WITH THEIR LACK OF RWY FLEXIBILITY PUTS ACFT AND CREWS AT RISK. WHAT IS ATC'S RESPONSIBILITY FOR A SAFE OP. ARE THEY SIMPLY A RED/GREEN LIGHT FOR TKOF; OR DOES ATC (TWR) HAVE AN OBLIGATION TO ENSURE A SAFE OP; TO INCLUDE DELAYING TKOFS AND/OR RWY CHANGES. ALL TWR DID HERE WAS RPT THE LOSS OF AIRSPD TO SUBSEQUENT ACFT. EVEN WHEN I REJECTED THE INITIAL TKOF CLRNC; THE TWR CTLR SEEMED OBLIVIOUS AND UNWILLING TO TAKE ANY SAFETY PRECAUTIONS.