IMO,
If you are merging/remerging and both fighters could put their nose on and fire with no problems, then they probably shouldn't, unless its a truly desperate situation for one of them (190A8 vs. La7 or the like). The outcome is just too likely to be unproductive for anyone.
Obviously there is a fuzzy area here, situations like scissors or high deflection shots it will occasionally be debatable.
People do however, exaggerate the ease with which a HO can be avoided. With some diving room or plenty of E to work with, can be done most of the time. In a slow fight on the deck, the MA being what it is, you should hose them down in return if they force you to it, to make sure the other guy doesn't get a scot-free kill.