Yeah. I think it's the result of conflating theoretical cryptography and practical IT security. Kerckhoffs's principle is true in the theoretical domain and it'

Yeah. I think it's the result of conflating theoretical cryptography and practical IT security. Kerckhoffs's principle is true in the theoretical domain and it's certainly important that the designers of standardised crypto algorithms adhere to it but it doesn't follow that it's pointless to change your SSH port.