I agree. Obviously 'god functions' and 'god classes' are bad, but splitting up tightly coupled, related logic into piles of <10 line functions seems ludicrous.

I agree. Obviously 'god functions' and 'god classes' are bad, but splitting up tightly coupled, related logic into piles of <10 line functions seems ludicrous. Not only does it hurt readability (and debugging) like you mentioned, but it also promotes false sharing of functionality. By splitting things up into very small functions many things may start to appear reusable. The moment it turns out one or two instances of the code that calls all these small functions need to have subtly different behavior you'll be hunting down each and every piece of code that calls the function, to be sure that changing it won't break completely unrelated parts of the code.