How do you know this crab is not an endangered animal? You don’t even know what it is. That’s why you posted your question, right?
By posting their ideas and opinions about the good vs bad points of private collecting, these guys are making others aware of it. You may see it as attacking you and your brother, but I think others see it as a learning opportunity for everyone, not just you.
This forum is great because it lets people state their opinions. If they say something that you don’t like or agree with, then move on and ignore them. If you don’t want the bad with the good, then don’t post at all.