I'm so sorry for your loss - but sometimes making someone comfortable, and allowing them to die with dignity, and giving their family the opportunity to say "goodbye" really is the kindest thing.
Having worked with surgeons in theist, i really don't believe that money is the bottom line. What they look at is likelihood of survival, how likely the patient is to recover without severe distress, and the quality of life they are likely to have afterwards. (Also, I can tell you that having a patient die on the operating table when you are doing everything you can to save them is dreadful.)
It is very difficult when you love someone to accept that their time has come - we would do anything and everything to save them - but often the patient dies on the table, and there is nothing that can be done, or they survive the surgery, but never regain consciousness - or worse, they do regain consciousness, and have to be so heavily drugged for the pain that they don't recognise family, or slip back into a comatose state. Sometimes people can hang on for days and even weeks like this, and it is dreadfully stressful for the families - knowing there is no hope, hoping anyway, and having the process drawn out. Or sometimes they will recover, but their quality of life is so badly affected that it's not acceptable;e.
You are bound to be distressed, but I honestly and truly believe that even in this cash-strapped environment, the NHS puts the welfare of the patient above everything. And sometimes that means making them comfortable, and allowing them to die with our pain or distress.
My DH is the same age as your uncle. I don't think he's old enough to die either - it would break my heart if he had anything like this happen to him, and like you, I would fight tooth and nail to get any treatment whatever that would give him a chance. But it wouldn't necessarily be the right thing to do. Please trust that that doctors took the decision with your uncle's long-term comfort in mind.
But I do feel for you, and for all who loved him. 