The emotional argument is played by Brexiteers and by ScotNats.
What’s good for the goose is good for the gander
There is a key difference here, Scotland is a net recepient of tax receipts from London wheras Brussels was a net recepient of tax receipts from the UK. We were propping up the EU, not the other way around like Scotland is being propped up by the UK.
The EU is also a protectionist minded bloc, impervious to the lesson learned by the British when we repealed the Corn Laws and shot to prosperity with free trade in the second half of the 19th century.
Besides, as I already mentioned I can appreciate the nationalist argument of wanting to be a sovereign nation on principle if you don’t see Britain as your country to whom you owe loyalty, but they should at least be honest about the economic damage Scottish independence would cause and state that independence would come at a heavy price instead of lying to the Scottish public about just where they are.