They're in it for the money. Stolen watch? Sell it on our platform, as long as we can deny knowledge. That's why they have a policy of denying knowledge on everything so they don't have any liability.
But if they don't have any liability, why do they charge a commission per sale? It's just a rotten system.
And don't think auction houses are much better. Their experts don't check every watch neither. And if they claim they do, then some experts are intentionally letting bad watches through!