Or is that just me being cynically twisted again?
Yes.
China is a very strange place, and we shouldn't always judge the people's actions by our own standards and traditions.
At one point, long before this event took place, China actually supported younger man / older woman relationships, as well as older man / younger woman ones. They even encouraged them, and doctors would prescribe a younger mate for certain low-energy conditions. There was no social stigma, no shunning by the townspeople. It was an accepted way of life.
Then the Communists took over. At the time of these two getting together China was undergoing massive social reform and many of the traditional ways were being not only discarded but outlawed. They couldn't go into town to work because they would have either been arrested or executed. When you have nowhere left to go, you do the best you can.
His action of carving those steps was an offering when he didn't have anything to offer. He gave his time, his effort and his health in carving those steps. He did what he could in that very limited situation to show true love.
It isn't always about comfort or money, at least it wasn't in traditional China. It was about honor and respect and yes, love. A simple and unmeaningful act to us, perhaps, but to them it spoke volumes.