I agree with OP, the "new" yellow tags are really easy to get torn off, and have happened to me. (although it doesn't really matter on domestic flights)
Side note, the green tag (one prior to current edition), was plastic coated, fairly durable for 3+ transfers.
Continental's new priority tag is plastic film(durable), and thin(Cheap). DL could switch to a kind, and still save the cost i think.