Earlier quoted context omitted.
It's malware for the mind. The same way that malware tricks the CPU into doing something it wasn't supposed to do, phishing tricks humans into doing something they didn't want to do.
Does anyone remember the early 2000s joke virus emails? The ones that are variations on "This is a computer virus. As we don't have software engineers to write the code to do this automatically, please kindly forward this email to everyone in your address book then format your hard drive." This is exactly as much malware as those were. Please, for the love of all that is good, can we just try not to build and defend…
A joke virus email is a sign saying "please throw yourself down the stairs."
An obfuscated prompt injection that tries to delete data is someone greasing the stairs and turning off the lights.
Both rely on the environment being unsafe, but only one is deliberately trying to make the failure happen.