When someone finds one of those Emue cards with 4 digits on the back clearly more worn than the others, I don't think it's going to matter how much encryption is used.

It's a lot more complicated to make a device or even modify one, capable of reading and passing along the credentials from a smart chip than it is to simply make something to dump the small amount of data from a mag strip. With that mag strip data you don't even need a PIN at all for the most part which is why it's not really any security at all. It's less secure than presenting your card and running a manual imprint - though of course the vendor has the benefit of immediate authorization.