I never said any Hellene ever damaged the Parthenon, though Demetrios Poliorketes did make its western chamber into his personal residence in 304 BC.

But let's look at just how protected it was over the years.

In AD 267, the barbarian Heruli sacked Athens and set fire to the interior of the Parthenon. Repairs were not done until the next century, and incomplete, at best, roofing over only the cella.

Under Justinian, they put in a crappy little apse and defaced the metopes on all but the south side and east pedimental sculptures went bye-bye, like as not into lime kilns.

Let's not even discuss the disastrous "restorations" done by Nikolaos Balanos in the early part of the last century.