I think the argument is totally flawed. Brains and eyeballs are biological. Perhaps biology is more bottoms up than top down or more like generate and test, yet it produces systems of incredible complexity that are remarkably robust. For example a human heart beats ~ 1 billion times, I've yet to see a human designed and architected pump do that. We just don't understand very well yet how the liver and pancreas work and western medicine is particularly weak in taking a holistic or systems view to the body.

Software, bad or good, is not like biology and it's not like construction. Software is mathematics.