We all need to remember, that until we've walked a mile in someone else's shoes...we shouldn't judge.
I don't think that anyone was truly condemning you, But I guess some of us just question the overall situation.
Personally, I understand the void you feel when a beloved pet gets killed and the hole it leaves in your heart. I too had a very beloved parrot get killed by my own dog. I still grieve for that bird. And even though I now have many many other parrots none of them can take his place or fill the void that was left.
However, I can also understand the questions that it raises in the fact that you took in two other birds and had one for 6 years and now you've recently rehomed them. With the reason behind it being your work schedule has changed and you felt you weren't giving them the time they needed or deserved. I can also relate to that.
What I don't quite grasp is now you are wanting to adopt a Macaw. And please, I'm not judging you. I'm just trying to offer food for thought and to try and understand your thought process. I guess what I don't understand is if you don't have the time to offer to a quaker and an amazon, what would be the difference with them versus a Macaw.
I understand also that you may have only taken the birds in on a temporary basis in your own mind, but to many peoples way of thinking keeping a bird for 6 years doesn't seem as though it was a temporary thing. Birds don't understand the Time thing. I understand quite well, how you take in a new bird thinking that it will be their forever home, and for what ever reason the personality of a bird and yours just don't click and you find the need to rehome them. I know too well about that, I too have had that happen and after a lot of soul searching decided it was in both the birds and my best interest to rehome it. However, it didn't take 6 years to make that decision.
So the question I'm posing to you is; knowing that you can't replace a lost pet in the way that it will fill the void left. You can show love and give care to others and allow them into your heart but no matter what even the same species will never be the same as the original one that was lost. I'm hoping that you aren't looking to "replace" the one lost, but to make room in your heart for another bird regardless and that it will be a forever thing and even if it doesn't have all the same qualities and personality that your original bird had, that you won't just rehome it after a few years just because its not the same as the first bird.
It can become a viscious cycle for people when they try to replace all the exact traits. It happens a lot because people think that because its the same species it will be exactly the same and it just doesn't work that way. Birds and any other animal are no different than humans; no one is exactly the same and to want them to be the same is setting yourself and the bird up for failure. Its not fair to the animal because they don't understand and the damage it can do to them emotionally is unbelievable. It breaks the trust they have and then its hard for them to bond with the next human because the trust isn't there and so they get passed on to another home etc etc.
So what I'm asking of you is to really do some soul searching as to why you want another macaw. Is it because you have room in your heart for another bird no matter what its personality. That you love the overall characteristics of a macaw and that you aren't just trying replace the lost bird. Also before you get another bird of any type, Stop and look at your work schedule and your life style, will having a macaw truly fit in with it as it is now. And what it might be in 2 years, 5 years 10 years. You owe it to yourself as much as the bird to make sure that it really will work. Because we all know how hard it is on us to give up a pet. Or would it be better to not replace the bird but fill your desire for them by volunteering at a shelter or rescue to fill that void. To get your bird fix.
Good Luck with your decisions.