It's not an option. It's what some people implement themselves when coming up with a PIN. Like "square" (4578) or "Z" (1379) or "triangle" (2792), etc.
That being said, I don't think the loss of shape ability would be that big of a deal. Neither do I think this is something that needs to be defended against.
Sorry, my phrasing was confusing. I meant that the pattern input isn't an "option" that phones provide, the way GP comment interpreted it. ("Take away the shapes option") Rather that it is a way some people use keypads.
I didn't intend to say a randomized keypad isn't an option.
I understood what you meant. What I'm saying is you have the chose of whether you will allow shapes to be an option. An always-random key pad makes it physically impossible to use shapes. That is "taking away the shapes option". It's not just the way some people use keypads. You can stop them from doing it on your keypad.
That being said, I don't think the loss of shape ability would be that big of a deal. Neither do I think this is something that needs to be defended against.