It's not just oil taking a hit, lots of commodities are down. The market seems to be discounting a global slowdown. If that turns out to be wrong, then you might get a quick bounce. If it is right, then patience will get you even better prices.
Hedge funds, etc., are heavy investors in MLPs and are now bailing on those shares, as usual. That's why.
The reason why I bought my oil pipeline MLP's is because I was under the impression that they didn't have as much exposure to volatile oil prices. So why have they been down almost 20% over the last month? I'm not panicking or anything, but I'm considering bailing out of them on any uptick in price. I really don't see the benefit of holding them if they don't offer any protection from wild oil price swings, considering their complex tax rules. On a related note, do you think now is a good time to buy a couple of oil companies at a discount? I'm considering Halliburton, Anadarko, and Continental Resources.