by committee

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

• adverb Through the collaborative efforts of multiple contributors, as a team or committee assigned to accomplish a goal; especially as known for protracted proceedings, a lack of responsiveness, or undesired results.
• adverb figuratively With any of the results cynically attributed to committee projects, e.g. unnecessary complexity, inconsistency, logical flaws, lack of a unifying vision, banality, lack of style or character, etc.