From Gary Becker:
The great majority of people in different cultures do not object to someone who has made lots of money when they have superior abilities and talents, and they work hard at producing what are considered useful goods or services. Actors like Tom Hanks or Jennifer Aniston earn millions of dollars per film, yet they are admired as stars rather than condemned for being millionaires because films are a popular form of entertainment. Bill Gates, Steve Jobs, and others who became billionaires by creating innovative companies that provide highly valuable goods and services to millions of individuals are widely admired as the business equivalents of rock stars rather than attacked for their great wealth. Leading transplant and other doctors who become successful and very wealthy through extensive education and superior skills are recognized for their valuable contributions to extending the lives of very sick individuals, and few object to their high earnings.
On the other hand, when hedge fund managers become rich by using arbitrage activities to narrow the spreads in interest rates and other prices between different regions (most hedge funds do not only engage in arbitrage) they produce useful services, but the value of what they do is not so apparent as the businessmen who make successful products. It is still harder for many to understand the usefulness of “speculators” who do well financially by successfully shorting shares of companies or commodities, such as oil, because they believe correctly that their prices will fall in the future. Their activities add value by smoothing out the prices of these shares and commodities over time, but few people like individuals who bring bad news, or who profit from anticipating bad news.