Joseph Rowntree even described the growing market for milk chocolate as a fad. Rowntree's poor performance in the category became a major problem from 1914 onwards, as British public preference continued to move towards milk chocolate, and away from the more bitter cocoa essence products. Rowntree's two major rivals, Cadbury and Fry, merged in 1918, and although Rowntree was invited to participate in the merger, the company declined to do so.
Joseph Rowntree, recognizing the growing popularity of milk chocolate as a fad, observed its impact on Rowntree's declining sales in the category from 1914 onwards.  As British consumers favored milk chocolate over more bitter cocoa-based products, Rowntree's company faced challenges. The merger of Cadbury and Fry in 1918 presented an opportunity for Rowntree to join the combined entity but he declined.