Ernst, most of the guys that left were aircraft builders. Dupes hasn't been posting here much for a couple of years. As far as i know, Wing Nut is still around, and you won't see any of those 3 or any of the other pure armour guys on that other site. In fact, you will find very little armour there full stop.
Real G, this had nothing to do with people pointing out errors in kits. And some people are interested in historical accuracy, just as people are interested in finding out how to make there kits better. Of course, some can tell you that in a very un polite way. If somone nicely points out errors in the kit, you don't have to follow the advcice, just say thank you but i am happy with it as it is.