I'll start the discussion by pointing out that heaving to is a means by which you can rig the boat to tend itself while you go below and rest. Sailing under bare poles is generally a means by which you can still actively tend to the steering of the boat. It allows some minimal control. In a lot of wind, the windage on the hull itself is enough to drive the boat downwind or on a broad reach at limited speed. It isn't a technique that is generally recommended, because it really doesn't usually drive the boat with enough speed and power to give you enough control when the boat is being pounded one way or the other by big waves. Big waves overtaking the boat from astern tend to cause the boat to slew off course and wallow. If one wave knocks the boat sideways, the next wave might roll it over. A little triangle of jib might help.
Scenario: You're daysailing in smallish (25'-30') outboard-powered sloop about 2 or 3 miles offshore and nasty squall/front/storm rolls in with the potential for 50mph+ winds. What would you do?
Funny you should mention it, but that happened to me Sunday. I was on a 28' inboard powered sailboat, and saw a 25' outboard powered sloop nearby, and both of us made it. Both of us took down all sails and motored downwind. If we had allowed the boats to get sideways to the waves, we would undoubtedly have been rolled over. We headed across (parallel to) the wind and waves in the lulls, to get closer to the windward shore, where the waves were smaller, and we bore off downwind in the gusts, when the waves became much higher and steeper, so we wouldn't be caught abeam by them.