Doesn't the design philosophy of a complex piece of software matter? Doesn't consistency of philosophy provide power by enabling separate pieces to integrate s

Doesn't the design philosophy of a complex piece of software matter? Doesn't consistency of philosophy provide power by enabling separate pieces to integrate smoothly? There's a legitimate discussion about tradeoffs to be had, sure. But at least since Fred Brooks it's been quite clear that conceptual integrity is valuable. And the concepts behind Unix have been shown to be consistent and powerful; Plan 9 demonstrated that there's still unexploited potential there. The Unix philosophy argument may be wrong in a particular case, but it shouldn't be derisively dismissed.