I'm sorry you feel that way. I don't for a minute feel like I have all the answers and I apologize if in an effort to help on subjects I'm pretty familiar with, based on decades of experience, that my answers could mislead because I misdiagnosed an issue OR technology has changed in the last few months. An opinion only matters if it's founded based on a vast amount of experience, not just a few years.
I assume if you were teaching a class on cinematography, if your pupils constantly told you how to do things and that everything you did was wrong, you would be pretty upset, wouldn't you?
We all have more experience in some fields and less in others. It's important to recognize your own weaknesses as well as your strengths. If you think that you have no weaknesses or gaps in your knowledge then you're not being honest with yourself.
I've only used the GH4 and Pocket cameras a few times. I'm not going to write long posts about their virtues and faults because I don't know enough about them. If Landon has shot with nothing but the GH4 for a year, then he certainly knows more than me and probably you too.
Similarly, I would defer to you on shooting with the Pocket as I've only AC'd with it a few times and shot on it twice myself. I'd expect that since you've only touched a C300 a few times, that you would defer to me since I do a lot of work with C100/300/300 Mk2.
Robin and Mark K have shot a ton with the F5, certainly more than me. They know what the deal is with that camera. I don't know anything about servicing film cameras, that's why I ask Dom for help since he had decades of experience doing just that. I'm not going to tell JD, Andrew, or Guy how to build a grip rig or run distro. I'm not going to tell Richard how to produce a movie. Or Greg how to pull focus. Or David Mullen how to do anything!
Having an opinion is fine. You're allowed, we all are. Say your piece back it up, and leave it be. If someone else finds it helpful, then great. And someone else has something to say, maybe try listening instead. Might be you'll learn something new.