I'll never understand this. They sell hard plastic passes for park hoppers. I just got my "exchange card" in the mail for my AP, which is hard plastic. Yet, when I go to get my AP at the parks, I'll get a flimsy paper ticket that is supposed to last an entire year. Why not just put AP's on the hard plastic?:shrug:
I've made this exact complaint in the past, and was told by someone who seemed to know what they were talking about that the paper tickets are actually more durable than the plastic ones. Evidently they're not actually paper, they're mylar, and as such are resistant to water and tearing. (I've kept all my old passes, but have not been sufficiently curious to test this).
I will say that they don't wear like paper. All my old passes still look like new. Also, I've recently (after 10 years) had my first experience with demagnetization. Both my wife and my pass were demagnetized. We keep them together in one of those little booklet/envelopes they give you with the passes, so I probably had them in my pocket with something that they shouldn't have been next to.
The cast member at the turnstile ended up scanning the barcode and checking photo ID, which was no big deal (though it was lucky my wife had her license, sometimes she locks it in the car so she doesn't have to carry anything), and after we couldn't use them for FPs we decided to go to guest services, where they replaced them with new ones with no problem. However, the cast member who helped me told me rather cryptically that they're allowed to replace the passes once, and that it if happened again it would likely be "more complicated". I don't know if this just meant that we'd have to show ID or something, or if it meant there was a chance that they just wouldn't do it - like I said, cryptic.
So anyway, after 10 years without ever physically damaging one, and only incident of demagnetization, I no longer worry about having the mylar tickets, and in fact I've come to prefer it for its thickness and flexibility.