why focus groups can cause failure

Just started reading Alex Bogusky's book 'Baked In'. Here's a taster:

Companies that are built by using mass marketing rend to develop their products similarly. They round the edges, smooth out the differentiating features and try to make products that work for the masses. They use focus groups to make sure products are 'acceptable'. These products certainly don't offend anyone, but acceptable is always the most risky strategy because acceptable is failing at an astounding rate in today's marketing environment...On the other hand, the stuff we notice is the stuff we tend to buy.