Blacksheep - in the link, they say that footrot bacteria are anaerobic. If so, trimming to expose them to air does have a sort of logic to it don't you think?
Yes, they do seem to be. As anaerobic is about the exclusion of oxygen while I could see the potential plausibility of removing barriers to the passage of air I'm not sure whether removing bits of hoof would actually make a difference. Oxygen travels ok in solution - otherwise our bodies wouldn't function - so in theory could still diffuse through a wet mushy mass caught under an overgrown hoof. A lot also depends on just how sensitive to oxygen the bacteria is - this does vary.
But this is where I was going with the "it's obvious" bit. The hypothesis that removing hoof will reduce anaerobic conditions which should then reduce footrot problems seems to have been tested and found lacking, suggesting that things aren't that simple. For example, although this may even reduce the bacterial load there could be other adverse consequences that outweigh that gain - for example a delayed healing of the tissue once exposed.
There do seem to be a range of other hypotheses (the Warwick link is a very interesting read) that have been tested and found to work - and that is the acid test - does it actually reduce problems. If not it doesn't matter how plausible the rationale sounds - it doesn't work.