I think it will always be difficult if not impossible for professional people to open up if they are still actively working. Even private conversations were tempered with caution when I was meeting other shooters face to face. You just never know when information given in the best of faith can be turned against you for whatever reason. Using the internet makes that even greater a commercial risk.
I imagine that the best we can hope for is honest discussion of real issues but ever in a sort of one-step-removed manner. General topics, yes, and specific experiences also, but only with enough caution to protect identities. As you suggest, you just never know who is going to be cruising the sites and picking up information and who might just happen to know the person or event you could be discussing.
Perhaps the truth might be that not that many pros use sites like this for the simple reason that they don't have the time. I do know that in my own day, I always had something to take care of, to worry about or to plan. It didn't mean I was always lucky enough to be working - there were good years and bad - and having a family also took up a huge amount of time and care even though I was lucky in having a wonderful wife who did far more than her fair share of any tasks.
Then there is the thing about writing. Some of us love it, some hate it and I'm pretty sure some simply fear it too.
It can also be an age-related matter, I suggest, with some younger people not all that accustomed to writing anything at all, and certainly with interests far away from sitting in an office in their spare time, banging on the keyboard even if the music coming in over the system is qite good. Also, perhaps the very young just don't have anything to report. Were I young and single, I'd far rather be out chasing a piece of skirt! Now that I'm old and single again, it just don't make no difference no mo'. Maybe that's what stops me buying a blasted sports car even though I could: why bother? There's a time for everything... maybe even for a more personal tide of posts!