No question that mentality exists, I'll argue that it's a very small minority of eg millionaires in any society that hold such a view.
There are around 11 to 13 million (not including primary residence) millionaires in the US; or around 4.5% to 5% of the adult population. The typical millionaire in the US is worth about $3 to $4 million. While it's a very large group of people spread across the country, they do have a few things in common.
The majority acquired that status from working extremely hard for a very long time, usually either operating and or selling relatively small businesses with no more than between a few dozen up to a hundred employees, or slogging away for decades piling up invested wealth slowly over their lifetime.
The millionaire class in the US is numerically overwhelmingly dominated by those types of outcomes and has been since the industrial revolution.
Extreme wealth on the other hand obviously is concentrated in a few thousand persons with unusual outlier situations, usually around very large business concerns. My suspicion is that group is dramatically more likely to have a master of the universe mentality.