IIRC, in the story of the Golden Calf, people not only actually MADE the idol but worshipped it, while in the story of Meraglim people only BELIEVED in what the Spies said.
Nevertheless, after the G"C, there was a long negotiation with Moses, people were pardoned and G-d allowed them to build the Mishkan to repent, while after the Spies, the whole generation was sentenced to death.
How this difference can be explained?