I guess we'll have to agree to disagree.
I do agree that it would be a money making exercise for domain salespeople, as with .eu, .biz etc.
However, Scotland does have its own distinct identity and is too often seen to be just a 'region' of the UK (as are Wales and NI because they are smaller constituent parts).
When I am looking for a product or service, I want to be able to find a Scotland based company as it would always be my preference to spend the few bawbees Gordon leaves me with this side of the border. Having a .sco top level domain would make that easier IMO.
I know some Scottish charities and voluntary organsations are also enthusiastic about having .org.sco in order to differentiate them from their counterparts south of the border.
And .co.uk / .org.uk would eventually become redundant if the union were to be dismantled... not that we're expecting it any time soon.