If this is done, pigeons are extremely hardy animals. If not, the breeder is leaving his stock open to various bacteriological and parasitic infections. But then, this is just common sense. Unless you're a dung beetle larva, the idea of fecal pellets for breakfast is not particularly appealing. The most important requirement as to pigeon housing is that the interior always be kept dry.
Dampness brings disease.
Pigeons are not ducks. Accommodations for pigeons range from luxurious racing lofts which costs upwards of a half million dollars to converted tool sheds. So long as feed is kept clean and the interior dry, each houses the birds just fine. The Levi books mentioned above, as well as others available from pigeon supply companies, show many ideas for loft construction. Breeders strive to raise birds to this standard.