The issue isn't typing them. The issue is that many "Security Questions" are secretly "Phone Passwords" because customer service representatives can see them in plaintext and will ask you them if you ever have reason to call them over the phone. Making sure that they are pronounceable (mostly) English words avoids some of the potential awkwardness of reading them out of your password manager over the phone, even if they are intentional random gibberish. It also partly avoids the social engineering trap of "it's just random garbage" because at least if it looks like words a customer service rep may still ask for them anyway rather than not bother to one-at-a-time review a series of random characters.