Very funny thread. I was amused by this when it got going more than twenty years ago, since with the small size of most lenses a metal housing made no sense. But then the fanboys started complaining about it, so they added the thin metal plate on the outside of the plastic mount to make them happy. Today the fanboys are shocked, SHOCKED!
to learn that the point of weakness was moved only a millimeter away and have taken up defending their rear metal cover as if it makes a huge difference in the wear-and-tear of the lenses.
This despite the clear evidence
offered that said metal plate covers are not any better or worse than the plastic covers. Of course, there must be something wrong with Roger's evidence, because certainly he would have more
mount repairs in the database if he restricted the definition
of mount to be just the outer plate! Hoo hoo!
My own experience confirms what Roger and Aaron note: the plastic mounts of lenses I bought in the 90's are not worn off, or exploded, or oozing mysterious plastigoo, and in fact show little wear over twenty years of use. I suppose one may eventually wear out. Maybe I could achieve this if I sat 2-3 hours per day attaching the lens to a body, then removing it, over and over and over... no doubt some fanboy will now be "testing" lenses this way and ceaselessly posting "durability" data on the Intertwitternet.
Fanboys remind me of the old couch potato saw: "Oh, sports? Yeah, I love sports. I could watch them all day."