End-of-Life Care

My paternal grandfather is 90. He has been in and out of the hospital recently for issues related to fluid retention and blood pressure. His doctors can't quite figure out what is going on with his systems. Every time he checks in, they tell him he needs to stay until they find the cause of his problems ... and then about two days later, they send him home, having not actually found the cause. So, what we're concluding is they're just not too concerned about him since he is 90. (Not to say he has been ill treated while he's at the hospital or anything like that.)
Last time he was in, the doctor suggested my grandfather would benefit from physical therapy. My grandmother, who is 83 herself, told him there was no way they could make it in to the hospital for regular appointments ... so the doctor just let it go. It was only after talking further with family members (my mother who worked in medicine for 35 years, my aunt who was a nurse for a similar amount of time) that she realized she should follow up. There is no reason why their insurance would not cover in-home visits by a physical therapist if my grandfather needs them. I don't want to ascribe motivations to people I don't know, but it really feels like they were letting it slide because he was 90. But being able to move his body better will dramatically improve his quality of life for whatever time he has left.
Well, the good news is my grandmother did follow up and now Grandpa Knapp is receiving physical therapy and will get a consultation from an occupational therapist to see how well he dresses and gets around with his everyday tasks. I'm so happy about that!
Why was it so easy for my maternal grandfather to get really expensive, massive brain surgery, in a split-second decision, which he probably was not going to survive because his day-to-day doctors were telling him he was not in a health situation where he could survive any kind of surgery, but it was so hard for my paternal grandfather to get something reasonable like in-home physical therapy? Something is seriously wrong with the way we allocate resources in our medical system.