It isn't just a mindset, it is supported by their accountant. Because of the way depreciation works their long term income is higher by buying new equipment than paying taxes.

The busiest week for farm equipment dealers is the week between Christmas and new years. That is when their account calls them and says trading in some machine would reduce their tax bill by more than the payments! Assuming the trade in value is high enough of course.

Farmers are businessmen running a real business. They understand how to use all the loopholes written for them.