M. Höhne wrote:

... but lately I see so many posts, in various places, not here, like ...

​It's here too.

A significant percentage of those who join this forum do so because they started working on a typewriter without really knowing what it was they were doing, and have dismantled components that didn't need to be dismantled, and now have a real mess on their hands. Sure, it would have been more ideal if they would have asked questions first instead of later, but at least they're trying, and hopefully learning in the process. This comes of course around to your question about what is destroying the most machines, and it would not surprise me at all if it was true that amateur repairs are destroying more typewriters than the world's postal services combined.

​My concern, in relation to the title of this thread, is how many enthusiasts there are who think that they are an expert, and give advice freely - sometimes terrible advice, because they are parroting someone else's bad advice -  even though they themselves have a lot to learn. I have seen this lead to conflicting advice being given in the maintenance sub-forum, and unfortunately the wrong advice being sometimes followed. The fundamental problem in this scenario is, who should a newbie trust? How can they differentiate between someone who has been professionally repairing typewriters for thirty years and the guy who just started collecting them thirty days ago?