In addition to avoiding double taxation and deferring the bulk of taxes, MLPs also benefit because they are relatively liquid investments for individual investors. That is, they can be bought and sold via traditional and online brokers (like stocks). If you are an investor looking for an attractive, stable return you might buy LP units. If your stake is not extremely large, you can sell those units at a later date in the open market.
However, as a side note, keep in mind that MLPs are NOT typically efficient to hold in a 401k or IRA. This is because gains are subject to UBTI taxes when MLPs are held in retirement accounts. Consult a tax advisor or the IRS for more details.
Also, “relative” liquidity is, well, a relative term. MLP units are still relatively illiquid securities from the perspective of large institutions. This means that, if an institution purchases a large block of units, they could possibly be unable to find a buyer for all of the units when they are ready to sell. This is one of the reasons these investments have not been picked up extensively by mutual funds.