"Manual" calibration was not the original form used in the game.
The system we have in use now was a derivation of it and a step back toward the original. Originally there was no calibration at all and it was a matter of just a matter of putting the cross on the target and it was a hit. That was very popular but was seen to be too simple with the increased firepower that the introduction of "drones" was to bring to the game. What you are calling manual was only used for a short time. It's biggest impact on the game was to drastically reduce the amount of people willing to fly bombers. Responding to the high level of unpopularity, HTC changed to a simpler form of the calibration system that essentially removes the direction aspect.
You are required to get solutions for height, speed and direction with "manual". You now are just calibrating to get solutions for height and speed, but not direction. "Originally" you were not required to calibrate solutions for any of these. Reductions in bomb blast radius and an increase in the randomness of speed calibration were brought in to balance the bombing power of the "trio".
The more complex calibration did make it much easier to sink ships. You simply calibrated on the moving object and it did all the lead sums for you. That was popular. It did however require you to keep your head inside the cockpit for lengthy periods of time. When you turned about to return to the target you had to start calibrating all over again. Since a fighter defence was usually active at this time, it normally meant that second and further calibrations weren't able to be done. It seemed that you never got more than one successful pass. Frustration abounded (and was expressed loudly and often).
People responded in a few different ways. The larger group gave up bombing entirely as it now brought poor results and chewed up a lot of time for very little impact. Others learnt the secret to making a game impact was to make only the first run and at bomb release, bail out, and get another trio on the way as fast as possible.
The other choice was to come in low and bomb everything from about 700 feet by eye. This became the most popular method in prime time. A small minority came in above 25k. Complaints by other players added to the noise coming from bomber drivers.
HTC, I suspect, will reintroduce "manual" calibration in the MA when they feel that their day is too long and boring and that dealing with a couple of thousand complaints from the community would be a great way to pass the time.
A system for handicapping yourself only would be acceptable of course. The problem, I'm guessing, is that it is a system setting currently set by a flag on the server requiring possibly a lot of work to change it to individual choice. I don't know. If it is difficult to do and requires a lot of work, then I'm guessing (again), that a great number of people would rather see them spending the time on introducing new bombing types instead. I know I would.
rgds
