As mainly a bottom-up person, I completely agree with your analysis but I wonder if you might be using "top-down architecture" here in an overloaded way?
My personal style is bottom up, maximally direct code, aiming for monolithic modules under 10kloc, combined with module coupling over very narrow interfaces. Generally the narrow interfaces emerge from finding the "natural grain" of the module after writing it, not from some a priori top-down idea of how the communication pathways should be shaped.
Edit: an example of a narrow interface might be having a 10kloc quantitative trading strategy module that communicates with some larger system only by reading off a queue of things that might need to be traded, and writing to a queue of desired actions.
My personal style is bottom up, maximally direct code, aiming for monolithic modules under 10kloc, combined with module coupling over very narrow interfaces. Generally the narrow interfaces emerge from finding the "natural grain" of the module after writing it, not from some a priori top-down idea of how the communication pathways should be shaped.
Edit: an example of a narrow interface might be having a 10kloc quantitative trading strategy module that communicates with some larger system only by reading off a queue of things that might need to be traded, and writing to a queue of desired actions.