Quite rightly so.
I just worry what you will do when you have an over population of mutt pigeons and cant find a home for them?
Pigeons breed like crazy.. you have to have a plan what to do with the offspring in the future.
If you only allowed the pure breeds to breed you would have little difficulty finding homes for your surplus birds.
As a pigeon owner you need to have plans for breeding them. Pairing up the right birds is good for the birds, ensuring healthy happy offspring.
You can also stop them breeding by dividing the coop into male and female parts.
Ask any pigeon owner and they will tell you just how fast pigeons can breed and increase in number lol.