I don't think the author's credentials alter the dynamic at play here.

Would it be better if he just kept quiet and let the health issues he is seeing go unmentioned because otherwise it would make people look bad? Do you think his book is just an exercise in mockery because he enjoys it?

"You suffer because of your politics" is laundering a political statement under the guise of health.

And yes, I do think mockery has become de rigeur in American politics, both left and right.

If people are indeed suffering because of their politics, is there any way to ease their suffering without making a political statement of some kind?

I think viewing things that way is akin to thinking wet streets cause rain. It is placing (often very selectively) an undue amount of agency upon a voter, whose effect on the political system at scale is essentially nil.