If I can use a custom keyboard to enter my iPad pin code -- problem solved? I'd of course point out that the pin code is the least of your worries given most apps' security when on unsecured wifi... Besides, this really is nothing new, as people have been remotely stealing PIN numbers for ages, even recruiting others to do it for them. That this is an iPad instead of a PIN pad doesn't make much difference.

That all said, I'm sure more people will buy into fingerprint passwords from articles like this ... which is just as insecure, someone can easily get your prints if they wanted to. Perhaps we need a bluetooth Yubikey plus manual entry for 2FA ;-)