ACR X NON ADHERENCE TO ATC CLRNC (UNAUTHORIZED DSCNT FROM ASSIGNED ALT) HAD CONFLICT WITH 2 WDB'S. PLTDEV.

Narrative

SEA FINAL CTLR WORKING NUMEROUS ACFT ARR DEMAND MEETING THE METERING RATE; MARGINAL WX. CONSTRUCTION ON THE ARPT CAUSING ALL JETS TO ROLL TO END OF RWY 16R. CTLR HAD TIME AND PROVIDED WHAT HE THOUGHT WOULD BE 'NICE TO KNOW STUFF' FOR ALL ACFT FOLLOWING A HVY. PHRASEOLOGY WAS; 'EXPECT A POSSIBLE BLOCK OF THE LOC WHILE THE HVY JET AHEAD TAXIES OFF THE RWY. CAUTION WAKE TURB.' AFTER ISSUING THIS XMISSION FOR AN HR; ACR X JOINED ME ON THE DOWNWIND; WAS ISSUED THIS 'STUFF' AND SAID; 'SO IS THE ILS OUT?' HOW CAN I GET TO THE ARPT IF THE ILS IS OUT?' I ADVISED HIM IT WAS NOT OUT AND THAT IT WOULD JUST BE A MOMENTARY THING; BUT HE PERSISTED HE COULD NOT FLY THE ILS UNDER THIS CONDITION; I ASKED ACR X IF HE WANTED TO HOLD UNTIL WDB LANDED; HIS REPLY WAS 'YES.' I INSTRUCTED TO HOLD NE OF ANVIL ON THE LOC; L MAINTAIN 70 AND EXPECT DELAY INDEFINITELY. WHILE ENRTE TO ANVIL 2 OTHER ACFT WERE N OF THIS FIX AT 60. ACR X DSNDED TO 64 ON A 90 DEG INTERCEPT WITH ACR Y AND ACR Z; BOTH HVY JETS. ACR X WAS GIVEN A TA IMMEDIATELY TO CLB TO 70 AND I NOTIFIED MY SUPVR OF A SYS ERROR. AFTER GETTING CHEWED OUT FOR ISSUING INFO THAT IS 'NOT REQUIRED' BY BOTH THE SUPVR AND THE AREA MGR. I ASKED WHAT ACR X HAD TO SAY. AREA MGR REPLY; I TOLD HIM 'WE' WERE SORRY AND COULD HAVE DONE A BETTER JOB. NO ACTION OR EXPLANATION GIVEN AS TO WHY ACR X DSNDED BELOW ASSIGNED ALT.