Airbus A321 Flare Logic

If you are flying manually the eyes should be outside to judge the height above ground and closure rate. Looking at the pitch indication is not going to give you the same visual cues and is therefor not used by real world pilots. Instead they use visual cues from the runway and also the automatic radar altimeter callouts. The flight director, when in flare mode, may indicate some target pitch value but this is also not really used by pilots for manual landings. The flight director guidance in the flare mode is only for reference for an automatic landing with autopilots engaged. It shows the pilots that the aircraft will indeed pitch up before touchdown. On top of that a lot of airlines specifically instruct pilots to turn off the flight director when performing a manual landing, so that they don't use the flight director for the approach and flare but instead look outside.

The actual pitch angle needed for the flare greatly depends on the approach speed, wind, weight of the aircraft and ground effect strength. A320 and A321 with sharklets have a stronger ground effect for example and the slotted flaps on the A321 also behave differently than the single slot A320 or A350 flaps. And a heavy aircraft at high approach speed handles different than a lighter aircraft. Raising the nose does not instantaneously increase the lift as well, so you need to time the flare just right. If you just pitch up to 5 degrees it matters a lot at which height you initiate the flare and how fast you pull up. And that "5 degrees" of pitch will only be correct for just one particular airspeed. If you are just a few knots fast that would mean you float. If you're too slow or pull up to 5 degrees pitch too late then you slam into the runway. There are just too many variables other than just pitch angle that need to be taken into account, that is why you can't just pitch to one value and hope it makes every landing perfect.