It's because the role of the Scottish Parliament is in deciding how a given block of money should be spent. A party that is in favour of lower taxes (and by ex

It's because the role of the Scottish Parliament is in deciding how a given block of money should be spent. A party that is in favour of lower taxes (and by extension lower spending) can only implement the lower spending bit - we'll cut spending and your taxes stay the same isn't much of a sell for a political party.