First off, the high productivity and large size of eggs from sex-link hens is usually a brief phenomenon. In most cases, high egg production is short-lived, lasting for one laying season only — the life span of commercial layers. What works for the industrial giants, may not work for backyard flocks.
However, moral issues are the real reason we won’t be getting Sex-Links this year. The industrialization of chicken raising has led to a problem of too many roosters. Although experiments with sex-linked inheritance in chickens have been conducted for more than 200 years, the development of commercial sex-linked hybrid strains started largely after World War II. Until then, it was just accepted that the ratio between male and female chicks would be half and half. Once hatched, the females would be kept for egg production and the males would be raised until large enough to be butchered. When the commercial sector turned chicken raising into a large-scale industry, chickens were specialized into either egg producers or meat birds. The dual purpose model was thrown out.
Under the new model, it was not cost effective to raise males of layer breeds. Sex-links provided an easy way to identify males, and the industry gained a reputation for destroying male chicks immediately, often through cruel and inhumane practices. It should be said, that commercial enterprises have turned Leghorns into laying machines, and production Rhode Island Reds are quite commonly used in “egg factories,” so even non-sex-linked male chicks can suffer the same horrendous fates.
A related objection involving the use of sex-links as industrial chickens is that these specialized strains have limited the genetic diversity of chickens and endangered heritage purebred chicken breeds. Even the diversity of sex-links has decreased in recent years. Where once there were a dozen or more independent enterprises specializing in the development of sex-links, now only two multi-national conglomerates, Groupe Grimaud and Hendrix Genetics, are responsible for almost all of the commercially available sex-links.