It is basically a second job.
Bottom line, the market will get you a great return over hte long run with little to no effort.
Real estate may get you a great return but it requires a lot more work like leverage (ie loans), property management, more complicated taxes, property selection, tenants, and other things.
Yes you could spend all that time and get something that makes it better, but it is a lot harder. That is why the stock market is generally better.
Now, I am planning to do some real estate investing for various reasons, so I don't hate it. It is just harder and more difficult to get the same return you can get with the market.