Why don't Scaffolding macros work if placed in a table header or a row with a table header?

Add-on:Scaffolding
Question:Why don't Scaffolding macros work if placed in a table header or a row with a table header?
Answer:

Scaffolding doesn't support macros in table headers or rows with table headers.

This is because Confluence will treat the whole row as a header and due Confluence's default behavior, it will not render the data that is inserted into the Scaffolding macro.