That's exactly why I like it--it's durable and the corners don't peel up because of the adhesive. I'll admit that it does take away from the clarity of the screen, but it's never bothered me personally.
I keep my phone in my pocket and have found that after weeks of pulling the phone in and out, the flimsy little screen protectors that you speak of usually start to peel off around the corners, pocket lint gets under them, etc. Maybe that's why Verizon includes 3 of them in the pack? Maybe I've just never purchased a quality non-adhesive based product.
I'm not trying to argue with you just for the sake of it. I really do like the Zagg product--even as a screen protector only. I agree with you about the full body coverage as well--it would look ridiculous on the Eris.