I highlighted the parts of your post that caught my attention. You may or may not be right about the material of the lock mechanism. There may indeed be a better material they could use and there is nothing wrong with offering your opinion about that. Said opinion would carry much more weight if you had actually owned and used the product being discussed rather than just seen pictures of it. I have owned a couple of the knives and used them hard and never had any issues. I also spend a lot of time on the forums and can't recall seeing ANY cases of the material failing except from human error when someone disassembled/assembled their knife.
One of the many cool things about Spyderco though is that they listen very closely to their customer base. They constantly improve and adapt their designs based on the feedback of their users. Hell, many changes (and even new models) have come about as a direct result of the feedback of the people on this forum. So welcome to the Spyderco forum and feel free to share your feedback and opinions here. Feedback on a couple of knives that you actually own would be even more useful. And who knows, you might even answer your own question in the process. You would be
far from the first who didn't really "get it" until they carried and used the actual knives.