I am receiving an increasing number of empty spam, no body text.
Spamcop does not accept this and reports "No body text provided, check format of submission. spam must have body text."

OK, spam is spam, body or no body text. Why not accept it?

You may want to read this Recent topic discussing spam with no bodies

My answer to your question is that the parser (software) expects a blank line and then text and so does not recognize anything that doesn't look like that. The reason no one treats it as a bug is because of the various reasons that a report of a spam with no body could be a mistake. In addition, it apparently does not affect quick reporting.

Miss Betsy