Marvin, I didnt expect for you to understand what I was saying about building a house with inferior products! Maybe someone else here can explain the context of what I wrote at your level of understanding a little  better for you with pictures and pop-ups LOL!

Buttertup, I am of the opinion that the rolling trait in rollers is most defineitly a genetic flaw that we as breeders try to perpetuate to "our advantage"! You dont see this rolling trait in feral or wild flocks of pigeons,for the sheer fact that even domesticated pigeons that have been let loose, after a few generations will revert back to the wild  type and coloration! Your analogy of Bulldogs and Pekinise  is a perfect example of how we as breeders of rollers compare to what breeders of these dogs are breeding for a "deformity"  !
Marvin even Tonys Rubys produce culls! So do every Thom,Dick and Harrys birds! The only difference is how the breeder chooses what is a cull and what is not! You know the old saying "one mans trash is another mans treasure"
Those who are at the top in any type of animal breeding cull very heavily!  You cant use the old carpenters  advise of measure twice cut once when you wish to have a stud of birds that are competive, backyard fliers or comp! I would not advise anyone to give  or sell thier culls to those who are just starting out either, A cull is a cull regardless of the reason! This unethical practice will only in time frustrate the beginer and cause him/her many years of wasted time! Ive been in the construction industry for as long as  I can remember, would you want be to build your home with inferior pruducts??

It has always been a puzzle to me as to whether rolling is a genetic flaw deemed a positive trait, not unlike the many fainting goats 'round our parts.  Perhaps we are breeding in a deliberate flaw and culling out healthy birds lol, but this is just how yer cute lil' bulldog or pekinese was developed hundreds of years ago or more. The reason for culling the birds for me, is that I am afraid if I didn't, within not too many generations, the rolling flaw or gift would be bred out of the bird, reducing the flock to regular street birds. Of course very deep rollers are also culled in the effort to create a balance and strive towards a breed standard of sorts.  This pigeon husbandry is  born out of my own logic not out of fact, but I thought Trammel would at least understand my own reasons for culling.   Peace out.

Thank you Cliff and Trammel, just trying to help everyone. 

Thank you, Tony, for providing this excellent background information for those tender-hearted and un-informed individuals who do not understand the many reasons and benefits of the culling process in animal husbandry and wildlife population management.
Cliff