The truth is very different. While 48 of Scotland's most senior nobles are associated with the famous document, which supports its medieval "parliamentary" provenance, it is now widely accepted that the supposed authors were neither present when it was drafted nor even consulted about its contents.
Indeed, the absence of their signatures has long been confirmation of that. Instead, the declaration was a piece of highly effective royal propaganda, formulated in the royal chancery, in which royal clerks sought to justify the Anglo-Norman Robert Bruce's murderous usurpation of the crown of Scotland. In this they were entirely successful, the pen being mightier than the sword, and 400 years or so of misery for the Scottish people followed.
Why we can't simply take our history straight and unadorned, as we take our whisky, is one of the great mysteries of the Scottish character.