Sarcasm, I presume.  

Actually,  the Rockefellers,  the Carnegies, the Ascots, the Roosevelts;  many extremely wealthy people who had nothing else to prove by making more money have often come out on  behalf of the 'common man' of their particular day.  

Many of them were  bigoted about blacks, the White Man's Burden, the Irish, the Chinese and lots of other things, and many were clearly  the opposite of Saints, but they still did that sort of thing for their perception of the 'common man' because piling up more money was boring.  

If you have a net worth in excess of a few billion dollars, what else are you able to or want to buy if you make another 100 million or so? 

Perhaps some of Trump's billionaires are there for those kinds of reasons; maybe not.