You're right in your criticism of our first past the post system.
But that didn't stop more than 0.5 million people voting BNP in 2010. They collapsed and no far right group has stepped up to take their place. The far right would rather hurl abuse at people outside takeaways or throw bacon at mosques. Until they are willing to organise themselves and display some modicum of competence, they will not be a viable electoral force, irrespective of our voting system.