Re-frame the question "I have to re-learn something" vs "I can just keep on doing what I am doing today", and I think you're pretty close to the answer.
I think a large part were just ”no” to anything. Few I imagine were against right hand traffic but many simply resisted change.
Only just half of voters voted, however.
I didn't expect Swedes to be so contrarian for the sake of it. Surely nobody likes to put the whole car in the oncoming lane every time to check if you can even start overtaking...