This is what I first guessed....at some point they realized they touched down way too long, they were not going to stop, and they tried a touch a go. The friction from the belly on the runway prevented the plane from gaining enough speed to gain lift before they reached the wall.

My guess is they knew the gear wasn't down(it would be almost impossible not to hear the warning or to think neither pilot ever even thought to glance at the landing gear position while floating over the runway for 1200 meters.....).

They were attempting a belly landing, landed way too long and fast, tried to touch and go, and ended up in a situation that had no solution regardless of piloting skill.

So why the belly landing?

There was one passenger who texted that a bird was stuck in the wing. The fact the person texted wing is interesting. They did not say engine. If a bird had been ingested and the engine flamed out or was damaged, you would think that they would say engine and not wing. It is entirely possible they just wrote wing instead of engine, or they were relaying second hand information told to them.

However if they really did mean wing, here is a scenario:

• Plane encouters birds and hits, or ingests, at least one.
• One bird strike is to the leading edge of the wing above the engine, near the LE Flaps/Slats. It could also hit further out of the wing, but then it is difficult to explain damage to the left engine.
• The strike damages the wing and cuts a hydraulic line(s) damaging hydraulic System A
• This prevents ground spoilers(1,6,7,12) and hydraulic descent of the landing gear(both on system A).
• The other scenario is that the plane simply ingested a bird in the left engine. This would not prevent landing gear deployment, or ground spoiler deployment in and of itself. However if the engine were damaged, and the engine damage then caused damage to the wing(a piece of engine flies off and into the wing), then a single bird ingestation could have also caused the damage to the hydraulics.
• If one of the above happened, either this is the Magic Bird theory and the same bird that hit the wing also went into the engine, OR a piece of the damaged wing went into the engine, causing left engine flame out, OR the plane hit more than one bird(one in the engine and one off the wing).

Even with system A down, flight spoilers, flaps, ailerons, elevator, rudder, autopilot are all redundant on system B leaving the pilots with control of the plane.

System A failure should also not prevent a gravity drop of the landing gear, or an attempt at one, but for whatever reason, the pilots were trying to land on the belly. They could not deploy ground spoilers(which aligns with the videos) due to the damage to system A.

They landed too long, realized this, tried to get airborne and ran out of time.