Let's look at a smart young grad's options:
1) Academia - Potentially interesting work. However, grad students are underpaid, overworked indentured servants in a vicious dictatorial status hierarchy (do what the PI says or you're out). Very poor career prospects, guaranteed negative return on time invested. The road to PI is sure to destroy your love of research.
2) Industry - Decent pay but work is extremely mundane. Very few "unicorn" positions which allow freedom for creative roles. No control of hours. Promotion becomes a very serious game of office politics, which can get very nasty.
3) Professions (Law, Med) - Enter at your own risk. Savagely competitive and draconian entrance requirements, incredibly expensive education, inhuman hours, constant stress at every milestone, and a never-ending barrage of standardized tests. However, if you endure, you can start your own practice and potentially have a comfortable life.
4) Entrepreneur - By far the riskiest option. Due to the get rich quick mantra of current investors, social/web/photo apps are the name of the game. Have an idea for a radical new research project with a long term focus? Forget about it. Build and flip is the only game in town. Build an app, get acquired or go go public, make your billions and get out. If it fails, try again, and again, and again....
So, now that we have looked at our options, can we really blame someone for going to work at a hedge fund? I can't. Especially if one is burdened with massive student debt. Ironically, hedge funds and investment banks pay employees much more fairly than any other industry, due to their profit sharing systems (bonuses). Meanwhile, tech industry execs are screaming over how high (!!) engineer salaries are, and are going across the globe to find H1-Bs and changing legislation to push those salaries back down.
If we want everyone to work on world changing projects, we have to set proper incentives. That requires a radically different setup than we have now.
TL;DR: Go to the hedge funds young man. Don't look back. Nothing else makes sense.