Google owns the vast majority of the web search market. When a single company dominates any market it often results in:
Inferior Product - Since competition is not constantly spurring innovation it is easy for products/services to stagnate.
Even if a company is pushing forward with innovation the lack of competitors using innovative methods to improve search (and we think Google is such a company) may result in a myopic product focused on micro gains within existing technologies.
Inferior Customer Service - Since there is no alternative, customers are forced to work with the company on it's terms.