The "lazy peasant" is a slander of the leisured classes: pre-modern farmers stopped short of maximum effort because their priorities were not served by more of it.

This isn’t because they are ‘lazy’ – the ‘lazy peasant’ (or poor worker generally) is a standard hypocrisy of the literature of the leisured aristocratic class towards poor farmers, today and in the past – but because they have priorities which are simply not served by labor maximization.