I’m not surprised that after centuries of being on the sharp end of English swords that Scottish nobility went “can we join and not get stabbed” I don’t care about any kingdom or king.

Well that's what the government at the time was, so unless you're appealing to some ephemeral spirit of the Scottish people of the 17th century that you as an American have a unique insight into, I don't see what you not caring about kings has to do with it