Yes, it is, but I've always said that that is a very short-sighted, small-minded way of looking at things. As if Scottish conservatives don't exist (they do). And therefore, in post- UK Scotland, say 10 years from now, a Scottish conservative party may well wipe the floor with an irrelevant SNP. It's a hypothetical, but not a ludicrous one. More ludicrous is to believe that the Scots are inherently left-wing, whatever happens ever.
I think there is a huge gulf between "inherently left-wing" and "left-wing
compared to the present Tory government", which is busy privatizing things even Thatcher didn't dare meddle with. There is a widespread notion that the centre of gravity of politics in Scotland is, very generally, somewhat to the left of that in Westminster - which, again, is not difficult. I'm not saying I believe this as a cast-iron fact but I remain open to the possibility that it might be basically true.
For what reason do you think it's likely, or even "not ludicrous", that a Scottish conservative party would "wipe the floor" with the SNP? Bear in mind that even in England, the Tories didn't "wipe the floor" with Labour last year - they got in because of our hopelessly broken electoral system. Let's suppose the oil market recovers, or imagine it hadn't tanked in the first place - why would an independent Scotland of the 2020s ditch a party that has successfully severed ties with Westminster, reversed the endlessly punishing austerity policies and is forging closer links with Europe while England languishes in xenophobic isolation?
I'm not saying the SNP is automatically going to fix all of Scotland's problems any more than Corbyn is going to be England's socialist Messiah, but I think it's at least plausible they could make things better for most people there than they are at present, or will be by the next general election.