The current variation was implemented in the March 2018 update to GSX thru Couatl Live Update.
I think a forum exchange in Feb 2018 led to the current variation.
http://www.fsdreamteam.com/forum/index.php/topic,17383.msg121997.html#msg121997
Yep, seems like it. I can understand users felt it was not realistic. But it's also not realistic to have these forced everywhere, even airports where the cargo stairs are just not in use. They could give the option.
Something like a icao prefix in the .cfg so you could add or remove airports where its visible/not visible.
Edit: If I had to give an example, it would be FSDT_Staircase_Fixed.
These ones are not used in Geneva either. But as these stairs have a .cfg file with icao prefixes inside, I was able to remove all instances of LSGG from them!
Edit 2: Looks like I did it!
I just had to remove the isCargo condition from the stairs I wanted to replace the cargo stairs with, and change the isCargo condition of the cargo stairs to
False. Of course I will likely have to re-do these steps at each Couatl update.