And I think you'll find you are very wrong. Sony was using chicklet keys on Vaios LONG before Apple ever used them. Sony weren't first either, as multiple threads on this board can attest to.
Oh? So if someone disagrees with you, they have no taste or are deluding themselves? Well, I am very happy with my "classic" MBP and think it looks many times better than the new one. In fact, I only bought my "classic" a few weeks back, giving me plenty of time to drink in the new design before purchase. I thought the new design was an ugly mess when they first released it and, 1 month on, I still agree with myself. That said, I have no problem with you liking them, to each their own. I support diversity of opinion, unlike you.
Mac's used to be set apart by their distinctive look. Now, they look like every other silver bodied, black screen, black keyboard rubbish that all the other manufacturers put out. I think that's the point the OP is trying to make.
And just how many aluminium cars do you think there are on the roads. Here's the hot tip: Not many. The Audi R8 springs to mind as one. A specialised car for a specialised need.
Plastic is a lot more durable than aluminium. Why do you think the "classic" MBPs suffered from so much flex in the screen? The MBs didn't have this problem (plastic). Not sure why you mention rust, do you think that plastic rusts?
In any case, I don't think that Mac's should be made of plastic, I like the aluminium look; however, I don't fool myself into believing it's a more practical or durable solution.
Damo