In my opinion two reasons. Magnuson Stevens Act "MSA" which has been revised a few times since being enacted initially in 1976 with focus almost exclusively on attaining an arbitrary SSB thresh hold level never before attained. You'd be hard pressed to find someone who can answer how that level was arrived at. So every year when SSB comes up short, immediately the mandate is reduce catch. That was the correct answer in the 80's when annual catch exceeded SSB. The biomass was being turned over every year, harvest was excessive and not sustainable. Once catch was brought under control, SSB started a significant climb until continued size limit increases caused a negative impact on reproduction causing SSB to reverse it ascent and provisions of MSA kicked in every year since starting in 2003 mandating again catch reductions year after year.

Second NMFS / ASMFC have to make this decision their way on their time frame and their terms otherwise by default they admit they've mismanaged the fishery for the last twenty or so years. No government agency is going to publicly acknowledge that, instead they hide behind the provisions enacted under MSA 42 years ago which is a convenient CYA excuse to fall back on. Basically we're stuck in a political black hole until the fishery is at the brink of collapse. At that time NMFS will have no choice but to step in, introduce a slot, maybe do what I suggested with the commercials which is absolutely needed but a long shot and say THEY saved the day. When that happens is anyone's guess.