The SNP only stood candidates in a small fraction of the country:
UKIP: 3881129 / 624 = 6,220 per area, winning 1/624
SNP: 1454436 / 59 = 24,651 per area, winning 56/59
Non-proportional voting systems are barbaric and anti-democratic, but when they're in place you might consider that voting for parties that can't realistically win to be a measure of how little your voters understand the political system or at best a protest vote. On the other hand, without large numbers of people publicly wasting their votes, then there's no push for change. The Green party explicitly told their voters to "vote with their heart" i.e. waste their vote, and have now suggested that the progressive candidates work together to avoid splitting their vote.
UKIP: 3881129 / 624 = 6,220 per area, winning 1/624 SNP: 1454436 / 59 = 24,651 per area, winning 56/59
Non-proportional voting systems are barbaric and anti-democratic, but when they're in place you might consider that voting for parties that can't realistically win to be a measure of how little your voters understand the political system or at best a protest vote. On the other hand, without large numbers of people publicly wasting their votes, then there's no push for change. The Green party explicitly told their voters to "vote with their heart" i.e. waste their vote, and have now suggested that the progressive candidates work together to avoid splitting their vote.