And they probably never will.
First off, other than a guide, or someone who hunts for meat and trade, what exactly is a "professional" hunter? Had I seen that listed as a major (liberal arts, I guess?) in college, you can be sure I would have signed up, and probably done graduate and post-graduate work, too.
I realize DFG says the population is in decline, but based on my own sightings elsewhere, and evidence of tracks and scat, DFG is wrong. The proximity to residential areas complete with natural food sources for deer (flower beds, fruit trees, acorns) makes these cats a nuisance worth taking seriously. Having lived near this sighting for almost 2 years now, and having spent many hours of my childhood in this immediate area, I know the deer population is massive. Where you have cat food, you usually have cats. I see, just driving around, an average of 4 to 8 deer a week. Mostly doe and fawn, but a good number of bucks as well. Cars take out some, but the great majority are a walking buffet for mountain lions. And local authorities must know this, as at least one local "open space" park has mountain lion warning signs at various points on the perimeter.
Solution - thin the lion herd AND the deer herd. If you reduce available food supplies, the cats will move on to better hunting grounds. One thing I'm not taking into consideration is predation on household pets, namely dogs and cats, plus other wild treats like squirrels, rats and raccoons - further population controls might be needed there, too.
Sadly, no one will bother to take this matter seriously. Even with plenty of attacks, and some deaths ,on the record, nothing really gets done about this problem.