Unfortunately, there are a lot of people on the internet who are, well, stupider than that spammer. Or not even stupid, but just ignorant about how the internet works, or mentally hiccupping in a particular way that isn't related to intelligence but may be related to age.

My mother, for instance, had to be admonished in firm tones not to even open email from someone she doesn't know. She's smart and educated and not suffering from alzheimer's; she just...didn't think people could or would do something bad via email.