Whilst there are no doubt several reasons why they don't post more often, one of them is certainly the reception they receive from a small minority of regulars here. Their experience, knowledge and wisdom is not always appreciated and is in some cases ridiculed and dismissed.
There is little incentive in trying to explain the proper ways and techniques to some of the architects & mba students here who are busy re-inventing the wheel and basking in their own self appointed expert status.
Translated: the other kids don't like me because I'm smarter than them, so I do not bother to suffer those fools.
By the way, any reception you receive is a direct result of how you treat others.