About 10% of the male population has some form of colour blindness, which is a fairly large percentage. Letting the market make decisions only leads to discriminatory practices. Worse, these practices can have an impact upon a person's life. For example: it can, and already does, affect employability.

Also keep in mind features that address a disability can be of benefit to everyone. For example: being able to identify something by shape can be useful to the colour blind, blind, and sighted people.