You can't blame the SNP for an electoral quirk which had given them a significant degree of power. But you could say the Eurosceptic wing of the Tories are doing exactly the same. They are really a party within a party.
Not blaming them at all, and fully accept the election result as a whole as it was by the current rules. Just think it doesn't fit the multi-party system we now have.
It could also be said that the Labour party are a party within a party. The hard left wanting to renationalise and the other side wanting to gain the centre ground in British politics.