Forgive me for not thinking "oh this is because of OBVIOUS performance reasons" like I'm a seasoned programmer. The answer is actually no I didnt
You are forgiven, now that you know the explanation...
Two completely separate animations would result in the animated guy object taking exactly double amount of memory (and there are two of them running together). It's already a very long animation, with over 4200 frames, which would double in size if the loading/unloading animations were separate.
The thing is, nobody complained about it being "weird" or "goofy" before and, as a quick comparison about how the animation has been improved since the FSX/P3D version:
- The FSX/P3D version of the baggage loader man was also a single one for loading/unloading.
- The frame count has increased from 1900 to 4200 frames, because before it loaded only 4 bags for each cart, now there are 11 bags, each one with an individual animation.
- The animation in MSFS uses Motion Capture with lots of hand-editing and cleaning up, the FSX/P3D one is hand-made.
- The number of bones in the character skeleton has gone up from 22 ( maximum possible with FSX ), to about 75. Since each bone has its own keyframes, to get an idea of the resources used, you need to multiply 75 * 4200 against to 22 * 1900.
- The FSX/P3D model ( excluding textures ) was 5MB big in total, the MSFS model is 18MB just for the animation, with 7 LODs levels at 14MB each.