Yes, it was explained before. JOSM's "improve way" and "replace geometry" functions were mentioned. Modifying elements instead of deleting them was mentioned many times. I have not received any replies or acknowledgements about this issue, nor has the mapper ever attempted to either fix it or avoid it to my knowledge, even after DWG blocks. They never asked me or anyone how to do this that I know of.

If they haven't mastered editing, then they should slow down, learn the tools and stop repeating mistakes. And they should fix the mistakes when they are pointed out. It is certainly not my responsibility to spend my volunteer time providing users with tutorials.

I have myself spent many hours fixing these. They have deleted hundreds of elements that I had to restore. And beyond that, I have reviewed close to all of their edits; fixed, and commented on them spending days of my personal time, including actually specifying what the issues are. And I don't see anyone else doing it or explaining or recommending anything to them.