It's not so simple. You got bit and you overcame it but that doesn't mean other people can. Actually for most people the most reasonable response to getting bitten by a parrot is to stay away from it. Some people can develop a classically conditioned phobia of the parrot after a traumatic first bite. They may want to get through and work out the problems, and yet they can't help feeling fearful or shaky. This can be counter conditioned over time but it would require a lot of desensitization on the person. Furthermore this fearfulness of parrot could drive more aggression because the parrot does not want to be on someone that isn't steady or predictable.
The reason I say a smaller parrot is easier for a beginner is because the damage/pain of the bite is less significant and it's much more likely that someone can get over it and keep trying. It's more likely to be possible for someone to be strong and ignore bites from a budgie or Senegal than from a Blue and Yellow Macaw. The reason people should not buy larger birds to start is because they have no way of gauging what a parrot bite is like and know what to expect. Despite what you say, the neglected parrots and full rescues would say otherwise. Many people end up giving up completely because they cannot handle the difficulties. What I suggest is that the smaller parrots are less difficult and therefore it is more likely that someone can overcome problems and stay through with it. The confidence and ability to read body language developed from experience with smaller parrots could help avoid/overcome biting with a larger parrot from the start rather than making beginner mistakes with a huge parrot and then having to pay in blood to make up for them.
As you will see from many discussions on this forum, many problems are easy to prevent but very difficult to solve. Biting, screaming, etc are very easy to encourage but very difficult to discourage. Once a parrot is shown that biting or screaming will get it what it wants, even after proper ignoring methods are applied, it still is likely to try those from time to time. If someone is experienced and establishes a no reaction system with a large parrot, they may be able to prevent these otherwise difficult (or impossible) to solve problems. If someone makes the mistake of reacting to biting on a small parrot, they will have to ignore bites to reduce their value and it will hurt but it may be a tolerable amount of sacrifice to overcome the biting issue. On a large parrot, taking 100 bites to show how it won't achieve anything may be impossible. Prevention would be key but without prior experience, even with reading/knowledge, the new owner may likely do things wrong and create bigger issues. Even someone who previously worked with smaller parrots can make mistakes with the bigger one, but at least many beginner mistakes (that can lead to long term problems) can be avoided because of experience.








