"Passion" is necessary for younger, non market dominating companies. It requires imagination, vision, drive to figure out how to compete against entrenched leaders.
As the business grows, passion and personal engagement with the product becomes completely unnecessary, and the problems of running the business move from problems of market penetration to problems of managing large numbers of employees, products, inventories, distribution channels, etc.
In other words, a smaller business is a custom, personality-driven enterprise out of necessity. As it grows the exact nature of the product or service that it provides becomes a commodity, not because it has to but because there is no penalty for it not to.
Microsoft need have no "flava", but an ISV better have a unique quality. Google need not distinguish its unique character, but a startup web portal had better have some overriding special buzz.
That's how I see it.