If you like to do business economically you can study economics, but there are many successful entrepreneurs who do not go to universities that they are rich from their own experience as well as their bravery so the need to study economics is not necessary.
It isn't necessary, but it helps and the people who are successful in business without going to college are probably outnumbered greatly by those who did (but that's just my thought; I have no data to back it up).
My major in college wasn't economics, but I took a few elective courses in economics--Basic Economics, Corporate Finance, and Intro to Econometrics. I enjoyed those classes enormously, especially the corporate finance one which was about stocks, bonds, derivatives and basically investing. Even if you're a computer geek (or pharmacy student), you should at least take one or two elective courses in econ, because they're pretty useful and interesting. Business never really interested me until I started making money, and I probably wouldn't have majored in that or econ, but I'm glad I took the classes I did.
If you watch TV at all, you probably watch the news. You constantly see financial reports about jobs numbers and the stock market, and having a bit of education in finance helps you to understand what's being reported. You don't have to be an entrepreneur to benefit from it.
For what I know, studying economics at uni means that you will have to go through a lot of nonsensical doctrine to get a bit of true knowledge. However, a college level education in Economics as a side subject can provide people with an understanding on how the world works around them and what can they do to take maximum advantage of whatever circumstances they have in their lives. It will not protect you from government misdeeds but may help you making the best decision to the case.