Adding this wouldn't be much of a problem if all airplanes used standard doors commands but, there are several cases that it wouldn't work:
- Airplanes using non standard ways to operate doors, like the PMDG. Right now, we read their custom variables, which is of course harmless, but *writing* might be dangerous, because you never know what else could be affected in a product we don't really have much control on. So we rather have the user closing doors, using any means officially supported by the airplane.
- Airplane the user has explicitly customized, in order to ignore a door status (using code = 0 in the GSX.CFG file), in this case, GSX has been instructed to simply forget about that door.
And course, even a combination of the two, like an airplane using custom doors, which has also customized to be ignored by GSX.
When we were in Beta, GSX had doors opened and closed automatically without any user intervention. Worked fine with default airplanes using default commands, but it was a mess with 3rd party airplanes, because each one had different issues and problems, so we removed the feature, and let it everything under user control.