Not to go off topic and this is probably a silly question, but is there any reason why passive pickups tend to be tape wound with plastic bobbins and not just housed in a metal case like an active pickup?
I assume it would affect tone but in terms of durability the only thing I worry about with my active pickups is one of the connector pins getting bent.
Edit: I'm guessing this would be similar to putting a metal pickup cover on a passive pickup, but I thought it might be different as well as actives seem to be much more tightly sealed than passive pickups with covers.