He’s not actually thinking “I must keep the masses poor”, but he’s also not thinking “I’m incredibly rich, it would be ridiculous of me to ask other people for money when I could just pay for it myself”.

And, while he may not actively do things to hoard money, he almost certainly employs accountants and lawyers who do everything possible to reduce the taxes he pays, including lobbying for loopholes in the laws if that would help their client (Mr. Rock) pay less in taxes.