a camel is a horse designed by a committee

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• phrase An expression critical of committees—or by analogy, group decision-making—by emphasizing the ineffectiveness of incorporating too many conflicting opinions into a single project. In this figure of speech, the distinguishing features of a camel, such as its humps and poor temperament, are taken to be the deformities that resulted from its poor design.