looks like it just wore out, too much hard shifting I guess...
The bastard part:
Looks like the inner bushing just wore out, nothing to do with the piece being plastic:
This is what it's supposed to look like new, next to the schnell one:
So basically, the moral of the story is you DON'T need a metal shift link. The part that actually wore out is just as susceptible to wear on the upgraded aluminum link. Oh well, I already ordered it....