I think the inverse is actually the truth. "Classic" physiological paradigms have failed only in the sense that that early findings were represented far too si

I think the inverse is actually the truth. "Classic" physiological paradigms have failed only in the sense that that early findings were represented far too simplistically by those who benefitted from simplistic models (pharma companies). No respectable neuroscientist has ever claimed anything even approaching a coherent understanding/model of mental illness. The discovery of gut/vagus interaction and its direct effects on mental function is simply an extension of the monoamine research. The enthusiasm for gut biome research lies in the fact that it's a relatively new field and may contribute a lot to our understanding of nature vs nurture (heritability vs environment) due to how gut bacteria cause direct and measurable changes to neurological function via the vagus nerve, which (at least in mouse models) directly affects behavior. This research isn't somehow replacing other ideas, but rather acting to supplement and help paint a more complete picture of a very incomplete understanding. I'm not sure what you're referencing by 'avoiding confrontation...'.