I had actually typed up a decently-lengthed response to your spam message and then I was told that you don't accept private messages. I was courteous and genuine when I should have spent no time and referred you to a local university for a lesson in Sarcasm 101. But, I didn't. I thought I would type out a reasonable response and was informed that you don't accept private messages.
For whatever reason that would be, I dunno. I can't imagine anyone's inbox getting so hammered with unsolicited messages that they need to actually block them all.
So, I'll just assume it was meant as nothing more than a move to try and antagonize.