I feel your frustration. I had just posted yesterday about wanting a larger parrot. African grey or macaw. I put it a application at my closest avain rescue and heard back today. They told me that the large parrots come with issues and they do not let people adopt without large bird experience. So I am back to square one.
Im sorry but that is on of my complaints with rescues. You have to be able to have a large bird or work somewhere with them to have large bird experience. If you can demonstrate with confidence that you can handle the bird it shouldn't be a problem. I understand that some rescue macaws might present a challenge if they in fact have issues and might be best to go to someone with macaw experience but to assume that all rescue Macaws have issues is a bit extreme. I never had a starter bird. I started with Macaws because I loved macaws and thats what I wanted.
There are a lot of Macaws out there that need to be rehomed that are not through a rescue. If your really ready to take on macaw ownership and don't want a baby then go an meet with some people that need to rehome their bird and see which one picks you. When a macaw likes someone they don't hide it.