Marketing aims to create consumer interest in goods and services based on the assumption that the target consumer is buying a lifestyle or habit, with some income, location and loyalty considerations thrown in.
It draws from information about the target demographic; however, personal preferences about color, type size, logos and so on do not represent those of the target demographic.
One person on a committee might be a target consumer, but certainly not the committee as a whole. Should people from disparate demographics second-guess the visual approach taken by the designer to the target consumer?