The real argument is that if the keys change, you'll know about it, because OpenSSH will yell very loudly about it. The random art is intended for _first time_

The real argument is that if the keys change, you'll know about it, because OpenSSH will yell very loudly about it. The random art is intended for _first time_ connections, where OpenSSH has to trust your judgement of the key's legitimacy because it has never connected to that host before. It's not like it will hurt anything, but turning it on for every connection doesn't make a security difference.