But trying to acquire the entire company is actually pretty difficult. You can buy stock on margin, but the rates are oppressively high, so it only makes sense to do so in short burst between expansion phases. But there's still risk, the economy can go south or the expansion may not be as profitable as expected, and if that happens, there's the risk of loans being called and your stock being liquidated.
I'd say most of my enjoyment of the game stems from the effort to amass a personal fortune. Eventually, you do learn how to execute various securities frauds, which is pretty entertaining itself.