Hi there, :welcome:
You ask “why” discourage breeding? Why not let the birds be birds and do as they do in the wild?
Of course every living thing in the world is going to procrate to continue the survival of it’s species. Considering that, sure it’s a natural process in the wild. But the budgies we keep aren’t in the wild. They’re kept in a confined space, and even our best attempts to duplicate nature in habitat and diet, etc. falls short of being authentic. The various circumstances under which captive budgies live isn’t “natural”, so we then need to look at how to keep these animals at their best in this “artificial” environment.
So much knowledge in so many areas is needed to successfully keep any animal, let alone complicate things with the added aspect of breeding. With breeding our pets, there will be factors to take into account things such as territorial behaviors and aggression, and the fact that many budgies don’t exactly ‘fall in love’ with each other and want to breed just because they’re simply a male and a female of the same species. Also genetics, are they for sure not related, are they in the best of health (beyond what you can see), what additions need to be made to the diet in preparation for breeding, etc.
In the wild, birds have all these things figured out instinctively, and seek out their own mates, figure out territorial boundaries with an unlimited amount of free space, and know just what to eat and what they don’t need during breeding and raising of a clutch. Also in the wild, things occasionally do go wrong, and it’s survival of ****est out there. With birds in our care in our homes, it’s part of our responsibility to do all we can for them and know what to do when something unexpectedly goes wrong. With an inexperienced breeder, the likelihood of ‘things going wrong’ is higher in this artificial living environment we’ve created.
In order to as best as possible duplicate the conditions of the wild, this takes a good amount of time and knowledge, as well as an openness of mind to learn new ideas and how to properly apply them. Also, observing behaviors of individuals under different circumstances, and knowing what it means and what needs to be done to correct, also takes time to learn.
The most responsible breeders (which is what we are trying to promote), have taken the time necessary to thoroughly research and observe.
You are not being cruel to your budgies by any means, by not letting them breed. No more ‘cruel’ than taking their ancestors out of the wild and forcing them to live in our cages and homes.