I haven’t thought about ASCII art text images being used for passwords in a long time. I remembered the idea when I read a post written by hackers who were trying to create software which would crack ASCII art passwords based on repeated characters.
ASCII art as a password is pretty unique still. Don’t worry too much about hackers cracking your password. Just make your ASCII art a bit more complicated, using more variety in the characters you choose and include numbers and letters too. Of course, the ASCII has to be one line too.
Think of it as a good reason to work on creating new one line ASCII art.