Well, my young adult niece is a lawyer, and her cursive signature is an important part of her professional identity. Maybe I inhabit a different world than the rest of you, but I have yet to see a signature that isn’t cursive.
According to Mnuchin’s own statement about that, because the “signature” would be there forever, he wanted something “clean” and readable. IOW, it sounds like this isn’t his actual signature that he would use to sign cheques or legal documents, but was motivated by egotism so everybody could see his name. I’m sure that there exists someone, somewhere, who actually prints their signature, but I’ve never seen it.
ETA: Yep, his original signature was an illegible scrawl ..