His opinion may not define his future in the forum, he's actually responding to what he has received in the forum. Yes, it's true, but isn't it enjoyable on the long run? When you look back and remember those days of criticisms from high ranked members you'd laugh about it. The forum is not against such criticism, members can say anything as long as it tallies with the aim of the thread. I'm beginning to see less of those responses. don't know if it's only newbies that get to see them in the forum. Yet saying that knowledge sharing is less, phonakAG, is a wrong statement. It's impossible to see an opinion that gets more than two critic response from top ranked members. Others will still share their opinion with the newbie and encourage him to improve. The issue most time is that newbies try to move faster than they should. Thereby, making blunders that will ignite being mocked by other members. I'd also use this opportunity to say, you should hang on, soon those responses won't be appearing on your screen anymore. The fun part of it, remains that high rank members don't mean to criticize your opinion. The truth is that they use it as a way to laugh and feel a bit happy. As though it's always funny to come across those responses, especially when it's directed to somebody else. No one would be happy to see it directed to them. As a newbie if you have the right response that is reasonably funny, you can send them back to the critic. Don't take them to heart, it's just a forum itch.
Moving faster as a beginner will be an advantage for them, but when they move too much and without control, as you said they will only make blunders and make the higher ranking people laugh.
There are a lot of such beginners, but some beginners also have their qualities, they can even surpass high ranks with good basic knowledge. It's best, regardless of rank, knowledge is important, reading from various sources and starting to learn how to think critically and of course participate in discussions well.