The three arguments that xinhui presents against a hangar on the 056 are crew comfort, role, and cost. Of these the last two are reasonable, while the first seems to be pure speculation on his part. Adding a hangar does not have to decrease space used for "quality of life". You may actually end up with more space after a hangar is added. A hangar would necessitate a second deck level in the back, like so:
View attachment 44234
While you lose the surface area directly underneath the helicopter (in red), you gain the surface area (in green) added due to the additional second level deck space:
View attachment 44236
That additional deck space could house whatever was lost by the red space plus additional space to be used for flight crew berthing along with extra munitions, fuel, helicopter maintenance equipment, etc.