From your topic, it's safe to say that what you call "highly professional knowledge" is about performing task to earn in here too? Like joining bounties(when they get to a desired rank), acquiring managerial skills and script writing etc?
I believe he meant the posts they make that are full of knowledge which are what he is calling highly knowledgeable contributions.
Some people need to understand that this forum isn't the only place to learn about Bitcoin and cryptocurrencies or understand everything about them. The whole internet is full of knowledge and information about cryptocurrencies, and we can see the craze and hype about Bitcoin and cryptocurrencies everywhere but if you ask, most of the people who are interested in cryptocurrencies know nothing about this forum.
So despite the fact that this forum is a great place to learn about Bitcoin and cryptocurrencies, there is a lot of knowledge outside of this forum as well, and those newbies who tend to have knowledge are newbies in this forum but aren't newbies in the industry.