I sympathise with your friend and, of course, his late father and agree. I've seen for myself that the quality of nursing staff is variable to say the least.
Nevertheless, I don't see that a change of government would change that. Maybe the target-driven culture of the NHS could be changed, but then people would probably complain about the lack of "efficiency". I'm not altogether sure how a whole health system should be judged.
When I was in a world-famous hospital after a heart attack, the treatment and care I received were excellent. I doubt if it would have been better anywhere in the world. The speed with which I was transported to hospital was phenomenal too, with emergency paramedics already diagnosing a heart attack and preparing me for surgery.
However, after the first 24 hours, the care definitely left something to be desired. Staff weren't available and were often off-hand, I couldn't be provided with low carb food and medications were sometimes late or even missed. There was no transport available to take me home and I wasn't allowed to use a taxi on my own and there was no public transport. I was told to make a GP appointment as soon as possible to continue with necessary prescriptions, but I couldn't get a GP appointment for five weeks and there were no community nursing or home visits. I had also been told not to drive or walk too far, but the GP surgery is beyond the distance I was supposed to walk.
It seemed to me that the root cause of most of the problems was lack of staffing, which is caused by underfunding. That's why I've recently joined a patient panel organised by the CCG. It might not result in anything, but at least I feel I'm doing something other than whinging.