Software that is not designed is not worth building.
Here follows opinions by preeminent, thoughtful and influential designers, thinkers and engineers. (I am inspired by the Berlin firm Man + Machine Interface Works' "the illustrious speak". Some of our favorites are their's too.)

‘Conceptual integrity is the most important consideration in system design.’

‘Conceptual integrity is the most important consideration in system design.’
‘A conceptually integrated system is faster to build and to test.’
Frederick P. Brooks, Jr. in his book ‘The mythical man?month’