Scotland almost entirely votes for Socialist candidates in Parliament. The SNP is socialist. If Scotland wants to wreck their own country with Socialist rule, that’s fine with me, but let’s not pretend that a “Yes” vote would be good for Scotland.
That is one possibility. Things like that have happened in many newly independent countries, usually where there aren't stable constitutional and democratic traditions: Algeria, Zimbabwe, Ghana, etc.
The other possibility is that the party system in a newly independent country may move back to the center. It's no longer a fight against foreign bureaucracy or foreign money or foreign media. People start to think of the government, the economy, and the media as their own. So, for example, after Ireland got self-rule a lot of the radicalism dissipated, and a century later they look a lot like Britain.
Something similar happened with our own revolution. It wasn't government or taxes per se that we were revolting against, but a government overseas imposing taxes on us without our consent. When we got independence and representation, we taxed ourselves more than the British dared to.
So there's at least the possibility that an independent Scotland will develop a viable conservative (if not Conservative) party and government in the future when politics is no longer a matter of getting back at the Sassenachs.