If you are able to buy a 150K home for 50K now that would be a good deal! However, you can't you have to borrow 100K in order to make this deal happen. This dramatically increases the risk of any investment, and I would no longer classify it as passive income.
The mortgage on a 150K place would be about 710/month (30 year fixed). Reasonably I would expect no more than 1200/month in rent, or 14,400. A good rule of thumb is to assume that half of rental revenue can be counted as profit before debt service. So in your case 7200, but you would have a mortgage payment of 473/month. Leaving you a profit of 1524 after debt service. This is suspiciously like 2K per year. Things, in the financial world, tend to move toward an equilibrium.
The benefit of rental property you can make a lot more than the numbers suggest. For example the home could increase in value, and you can have fewer than expected repairs. So you have two ways to profit: rental revenue and asset appreciation.
However, you said that you needed passive income. What happens if you have a vacancy or the tenant does not pay? What happens if you have greater than expected repairs? What happens if you get a fine from the HOA or a special assessment? Not only will you have dip into your pocket to cover the payment, you might also have to dip into your pocket to cover the actual event!
In a way this would be no different than if you borrowed 100K to buy dividend paying stocks. If the fund/company does not pay out that month you would still have to make the loan payment. Where does the money come from? Your pocket. At least dividend paying companies don't collect money from their shareholders.
Yes you can make more money, but you can also lose more. Leverage is a two edged sword and rental properties can be great if you are financial able to absorb the shocks that are normal with ownership.