I think a designer should be free-er than picking options, but it really depends what's being designed.
Designing for government websites or huge worldwide e-commerce sites - both with tons of moving parts - requires a lot of constraints to make sure they work for everyone.
Designing a bespoke website for a prestige brand - while it should remain accessible of course - must be so different. And there's grey area in between.
Or have misunderstood the discussion?
