@Daygloboo Quality of life and Quality of life years (QALYs) are measurable things, used in research.
What you think, what you want is only relevant to you. If you want to spend your whole life caring for your parent - crack on.
Others don't want to spend their lives this way, or do so but would like some acknowledgment that it comes at a cost to them - in time, in money, in enjoyable years of their life, in time with their other family members - and in my experience it sometimes comes at the cost of their own lives.
What you don't get to do is to tell other people that because you're happy to do this that people who think differently are wrong - as you said 'who the hell do you think you are'