Someone can say that the quality of life is a concept for many reasons. If you are going through a gard time or are miserable, you are not going to say that life is great and its about the quality of life. Therfore making the statement that it is just a concept. If you are living a successful life, quality will be everything to you. It is just a concept because the human brain agrees with something based on their particular situation. It is a subjective concept because there is no certain and set-in-stone answer.
