alternator

[L.Fite]

QUOTE:
Not saying anyone is wrong, I just don't understand how it could be a problem.

I don't think the problem is actually the "alternator" as it is the "regulator" that is getting zapped...

If the alternator is putting out a high amperage and the switch is turned off, it sends a spike through the regulator which is a bunch of made in china electronics, diodes/SCR's and such.
Electronic circuits don't like sudden changes in volts/amps.

Back in the day the external regulators were relays and ceramic wound resistors, and while not bullet proof, could handle a lot more in the way of hard use.