Why do people insist that when birds talk they have no idea what they are saying

Conversation wise between my macaw and amazon can be quite entertaining. When Baby wants me she tells me to come here. When I am doing something that Fuego cannot see he asks "what are you doing" They both tell me goodbye when I leave, they welcome me when I come home. Special treats are welcomed with Mmm good OR hey, THANK YOU! When they need extra attention and I cannot give it to the instantly the tone changes to almost a whine, kinda like a child begging. I don't know but sounds like they can put two & 2 together pretty darn good. This is only a small portion of the interesting actions that keep me in awe every single day..Any input?

You are absoluteIy correct.

It is possible and it has been proven that parrot are cognicent. Dr. Irene Pepperberg rocked the world of Science back in 1999, when she published a paper titled: "The Alex Studies- Cognitive and Communicative Abilities of Grey Parrots". She developed what is called "The Model-Rival Training Techinique". This technique uses 2 humans and a parrot "subject" to not only learn "language", but the actual meanings of the words. Alex, her African Grey Parrot is now world famous for his extensive vocabulary and comprehension of words, phrases, and labels of objects, matter and color. He understands the concept of size, shape, category and sameness He also has proven he understands the concept of zero.that is, the absence of an object.actually a very difficult concept to understand.