The only caveat to the final point - and any time one person is given decision making power over something, is to give the community a chance to voice their desires and preferences up front. Not necessarily feedback, but a compilation of preferences that a designer can use to make sure they are creating something that accurately reflects the needs and desires of the community as a whole, not just their own personal preferences, or guesses at what everyone else wants. This way democracy can still be involved without the negative side effects you describe above.
4 Do's and 3 Dont's on coliving space architecture/design
The only caveat to the final point - and any time one person is given decision making power over something, is to give the community a chance to voice their desires and preferences up front. Not necessarily feedback, but a compilation of preferences that a designer can use to make sure they are creating something that accurately reflects the needs and desires of the community as a whole, not just their own personal preferences, or guesses at what everyone else wants. This way democracy can still be involved without the negative side effects you describe above.