Warren Buffett wouldn't be where he was if he wasn't obsessed with money. But to your point, that doesn't have to translate to material goods: the bigger house, yachts, etc.
When I was younger I rented furniture from a company called CORT. I happened to notice on the contract or receipt or something, that it was a Berkshire company (I didn't know that before then).
If I were Warren Buffet, I would have been happy to know that someone was a satisfied customer of one of his companies. I got some decent furniture for a few months at a reasonable price.
Just like I'm happy when someone is a satisfied user of my software.
If he believed in them as an investor he helped build the companies.
He took Berkshire Hathaway, a struggling textile company, and transformed it into one of the largest and most successful conglomerates in history.
You can see this behaviour in online multiplayer games that have a currency aspect --- some people will spend almost as quickly as they earn, while others will save some and buy items as they can afford, and then there are those who will just keep saving and saving, rarely buying.
The score keeping aspect makes it interesting, just like playing tennis while keeping score is more interesting than just hitting a ball back and forth across the net without counting.