Negative campaigning

Compared to Danish elections campaigns, the British ones are typically very negative. I can understand it makes good sense in a two-party system using first-past-the-post.

However, I fail two see it really works when there are more than two parties with a chance of getting elected, and in particular with a proportional system like the one used for the Scottish Parliament. Just look at the photo here: It’s quite clear that something horrible will happen, and if you read the text underneath, it’s also clear that the intended culprit is the SNP, but it isn’t underlined very strongly that the suggestion is to vote Labour instead. One could quite feasibly see this and decide to vote for the Tories or the LibDems instead.

I don’t understand why people don’t go on study tours to countries with proportional representation to get some ideas about how to campaign instead of continuing with the old-style negative campaigning.