@afrobin- I think that you are talking about extremes. I believe that some of us are simply saying that a bit of appreciation and concern is an appropriate response be an adult child. I also think that not saying thank you for gifts is inappropriate behavior for an adult child. I am not talking about adult children with severe mental health problems.
When I fly to visit my son, who lives on the opposite coast from me he picks me up. He lives about 3/4 hr away and unless my husband and I rent a car I expect him to do this. I do not feel that he is burdened by this, nor does he.
I think that when our kids have kids their thoughts should be with their kids and what's best for them. If a child has trouble sleeping then interrupting a nap might not be the best idea. Some kids adapt very well to being woken up and taken anywhere, some don't. When I was a young mother I really hated to wake my son up, for anything. I missed doing things and felt selfish sometimes but that's what I did.
Perhaps we need to make alternate plans if our children can't make it to pick us up, take us to an appointment, or whatever. If I lived alone and my son lived near me then I would not hesitate to ask him to help me out. I do feel like a pain when I have to rely on anyone, but that's what mine does. I think that there is a difference between being a burden and being a part of a family.