Business requirements evolve. Even if you ship a working and currently-satisfactory product quickly, you don't know whether an architecture is good or not until

Business requirements evolve. Even if you ship a working and currently-satisfactory product quickly, you don't know whether an architecture is good or not until you see how it copes with new requirements 3, 5, 10 years from inception. People changing jobs/teams faster than that may simply never experience a feedback cycle on the real, long-term quality of their work.