From Seeking Alpha:
Fixed-income securities are the preferred choice of investors who are ready to forgo capital growth for regular income flows. The expense involved in creating such a portfolio of bonds from different categories may be quite considerable. This is why most investors select mutual funds since they are a convenient and affordable method of investing in bonds. Also, diversified bond funds further reduce the risk involved by holding securities from different sectors. A downturn in any one sector therefore only has a partial effect on the fund’s fortunes.