I don't know if avoiding liability for their products is great way to make money or not. But if they are making a large effort to avoid liability, they are doing that as a way to guarantee profits - ie, make money.
Deere effectively has a monopoly on tractors at the scale discussed in the article. That's why farmers are buying the tractors and illegally moding them rather than buying competing brands - see comments elsewhere on this page.
And, of course, they're leveraging new legal concepts which allow them to sell their tractors while maintaining control over them through software licenses.