To my understanding enough was known by 1944/5 about the holocaust and unwarranted Nazi aggression to give the Allies the upper hand in public opinion in a liberal society. Why didn't Sweden and Switzerland join the war? Couldn't they have been a thorn in the retreating Germans' side in Norway, Northern Italy, and Southern Germany? If their excuse was always that their geographical position made war futile, why didn't they join to do their fair share once it wasn't strategic suicide?
Because they where officially recogniced as permanently neutral powers, which gave them certain rights and responsibilities under the Hague convention of 1907. If they went to war they would lose that status and they would properly have a hard time getting people to recognize their permanent neutrality again. Also such a move would properly not have given them any amount of goodwill from the victories allied, so political they wouldn't have gained anything from such a move.
Also remember that not all people looked at the second world war as a fight betwen the "good" allied and "evil". Many people feared the spread of communisme even more than nazisme and both sides of the war commited terrible astrocities. A good example is Sweden. On one side Sweden saved many thousands of jews and served as a refuge and training camp for norweigen and danish freedom figters, but they also supported Germany and Finlands war against Russia.
Swiss neutrality was acknowledged 1815 at the Vienna Congress. They built up 130 years of neutrality until WWII. Why would Switzerland sacrifice that to get into a war against an already doomed power?
Also: Even a german army on the retrat could have caused massive havoc in Switzerland. So why endanger uninvolved civilians? And not everyone in Switzerland sympathized with the Allies at that time...