There's boxes with sharp edges all over that thing. It looks like an afterthought. They could have done better by maybe grouping them into one large structure on the belly right behind the front wheels, or enlarged the body slightly to mount them all inside providing the rear sides of these sensors some armour, or even kept them the way they are, but not put them inside boxes with pyramids like that thing on the stub wing.
This is an upgraded variant of an existing airframe/fuselage -- if you are adding in packages like new sensors (AESA MAWS, ESM on the fuselage), countermeasures (DIRCM on the stubwings), and armour pads (engine and cockpit adjacent), you aren't going to tailor and redesign the fuselage for that.
Otherwise you may as well design a new helicopter wholesale.
Placing the DIRCM at the bottom of the fuselage
could have been feasible, but based on the size of the overall DIRCM pod on top of the stub wing, it is apparent that they take up meaningful volume and it is very possible that Z-10 as an airframe does not have that sort of excess volume on the bottom of the fuselage (it is a 7t aircraft after all, lighter than a AH-64, Mi-28 or Ka-52 class helicopter) -- and alternatively if it were to be placed protruding out from the bottom of the fuselage then it would protrude out and potentially offer unacceptable clearance to the ground.
Furthermore, being mounted on top of the stub wings may also offer benefits in terms of providing greater coverage and also greater ease of access for maintenance. One might ask "why not mount the DIRCM package more lateral on the tip of the stub wing rather than on top of the stub wing" -- well the most immediate natural answer would be that being mounted on top of the stub wing reduces the span of the stub wings, and more importantly mounted on top of the stub wing offers greater structural support than having to mount it on the tips where they would have to support themselves (again, the ability of the stub wings to structurally support payloads or pods in this case is dependent on its structural bearing capability which in turn is dependent on the aircraft's overall MTOW as designed, which is lighter than Apache, Mi-28, Ka-52 etc)
There's also the fact that being mounted on top of the stub wing and looking like there are "boxes with sharp edges" literally doesn't matter.
In general -- if the question is "why is something mounted externally rather than integrated" the answer is almost always a combination of "unable to integrate to hull/fuselage/airframe due to volume/weight/cooling/power demands" or "clearance/maintenance/coverage requirements".
And if it's because you dislike the aesthetics of it, then well, beauty is in the eye of the beholder. And maybe care a bit less about aesthetics to begin with.
You keep making some odd complaints and questions, like wanting the PLAGF's truck SPHs to be fully automatic, despite obvious answers as to why that was not pursued nor feasible.
At least, if you want to ask these questions can you not make it sound like your assumption is a natural and obvious conclusion, and to put some effort into the question?
.... Frankly, for a 7t helicopter, the Z-10ME as depicted is rather well equipped. A mast mounted radar, enhanced ESM, AESA MAWS integrated with DIRCM, retaining upturned turboshaft exhausts for IR suppression, and a reinforced armour package, all with the usual turret, four hardpoints -- that is probably about as much as you can squeeze out of a 7t helicopter with contemporary technology, and frankly there should be little that one should complain about with the package as a whole. If anything it's impressive they were able to put everything together in a single aircraft like this.
There is even misspellings "when manipulate" and "at towing".
That's just because they don't care much about English showing at defense expos (regardless of whether it's domestic at somewhere like Zhuhai or abroad), that has no bearing on the integration of the subsystems on the helicopter itself, which we've already seen in flight test years back. You can be assured the integration of the subsystems would be done with regular due diligence of any other product.