its sad that these devs don't take the placement of AI traffic into consideration when they are creating the scenery
It's much more complicated than you guys think :
First :
Airports developpers
are focused on creating a state of the art scenery, visually. Most of them are not filling their sim with AI traffic,
they just don't have the time to look for everything or learn about how to auto install all those, handle AI-specific problems.
Users install and use the pro sceneries, they also install a bunch of AI, they have the time because they are not required to work on a scenery 5 days a week. They do spot the problems you're describing. But the difference is there : you all have the AI variety from FAIB/FSP/Raven/UT/whatever, the scenery developpers don't (or doesn't bother to get the perfection on that side of the simming)
Second :
AI aircraft and parking spots. You must understand aircraft are considered "correctly" parked at the gate
by the simulator when their center of reference as designed in the model by the AI aircraft modeler is colocated with the center point (coordinate) of the parking spot. While reading you, I'm under the impression you're assuming the aircraft nose gear, or maybe the front door has something to do with how far away from the terminal the docking aircraft will stop. There is no such thing. Everything is about center of parking spot, and center of aircraft model. Now, each single AI aircraft model was built with its own "center" (the x:0, y:0, z:0 coordinate in the 3D modeling tool). You take a Boeing 767-300 from AIAardvark, a Boeing 767-300 from FAIB, and a Boeing 767-300 from FSPXAI, and
those three will park differently on the very same gate.
No matter how effort you would make in ADE, the only thing you can do is compromise between the three. But even then, when all three 767-300 are somewhat okay on that gate, the moment a 747-400 gets there, KABOOM ! That's just what is called simulator limits. The feature you wishes for is just not there yet.
Third :
Wanna get improved ADE ? Visit
AIG/Alpha India Group on a regular basis to spot for new ADEs on pro/payware, pro/freeware and default airports. Or at least try Avsim search with "AIG" keyword (or probably directly the name of the few AIG ADE makers), in the appropriate Avsim subsection (Afcad/ADE/corresponding sim version). Those (re)works are what are called "compromises", which takes account of the most probable aircraft and operator using each gate. You said "perfectionism", that also means "ability to understand what is currently possible" and "I'm prepared to look for the best on my own (assuming I find out at least an hint - that's the purpose of my post)". AIG specialises on AI traffic, are also "perfectionists" on this side of the sim, meaning they, at least, try to get the best humanly possible with what we (can) have. But because we are all just humans, there are still errors and limits we can't overcome.
Last :
You may argue,
but wait, we do have those nose gear stop exactly where the associated ground marking (B747 or whatever) is in the scenery !?!? Yeah, that good for you, but that's just by chance, unfortunately. You should understand a 747 is longer than a 737, that's a fact that doesn't change in a 3D modeling tool. Therefore, a 747 model compared to a 737 model will likely have its nose gear farther from the center (origin) in the modeling tool aswell. The way you find out where the sim limit is, is to find a scenery with stop markings of a widebody nose gear at exactly the same position of a narrow body. ie, find "a B747 (must stop there)", and "an A320 (must stop there)" aswell, same nose gear marking location, not 20ft behind/farther. There you will see, despite the scenery seemingly taking care of stop position (visually, as in real life because it's a virtual reproduction), the simulator just don't handle that.

Hope that will bring some light on who can do what and why.
Who would you blame now ? <- this is just to invite you to revise the situation, and help you
enjoy what is available, maybe encourage you to bring your piece of future solution(s) for future sims. This is not to make morale, to make you think to much about, or to try to find who's "guilty" (no one get any benefit whatsoever from that)