A system not supporting non-latin characters in personal names is pitiful, but a system telling the user that they have an invalid name is outright insulting.
While I agree with you that an error message like this should not be taken as a personal attack, it still causes a horrible user experience. It’s not like the developers of these systems had no choice in the wording of these errors: they picked the insensitive computer-says-no option, while they could have went with an apologetic “Sorry, our system does not support special characters” instead.