Many people (sadly) view parrots (especially the great big ones with beautiful plumage) as flashy decorations. I mean, haven't you heard "he who has the biggest wins"? But unlike your 82" flatscreen mega-super TV and ultra iPhone luxury edition (you get the point), a large parrot is NOT something to show off to your friends and look at in awe as you admire how "awesome" of a person you are for being able to afford to own one.
Those "types" of people tend to buy very large parrots (i.e. big macs and big too's) as a luxury item and once the novelty wears off, the bird has to go. They don't care one iota about the bird, it's no different than any other "outdated" material possession to them. That's why you see so many big birds up for sale, adoption, "free to good home" ect... This time of year is a good time to offload an unwanted bird before you jet off to your favorite tropical locale for summer vacation (and you might score some extra vacation cash getting rid of that "thing). You see a lot around the holidays too, people getting rid of them for Christmas cash. It's a sad, but true reality for many of these sensitive, special creatures and (if you can't tell) it pisses me off to no end!