Probably because there's a lot of things that still aren't present that are being worked on. The ability for the tug to pull the plane, lavatory service, not sure what else off the top of my head.
Nothing to do with hand signal, that is a standard phraseology always used during pushback and has well higher priority over what you described. Not having it is 100% unrealistic, even because you never know where the marshaller is at the end of the pushback... It was also used in Aerosoft AES.
I'm having a hard time taking you seriously when you think that everything you suggest has a higher priority over everything else and that they should just drop everything and work on what you suggest. GSX is under constant development, so did you ever consider the possibility that they either missed it or simply hadn't thought of it? There were certain aspects of the pushback that weren't realistic that eventually were corrected after suggestions from various people. Before, when you initiated the pushback, you would select which direction to push, then the tug would connect, and off you go. Several people brought up the issue that the tug is normally hooked up, so once pushback clearance is received, the push can start right away. The problem is that you might pick one direction, and the controller might issue a different direction, in which case you're screwed. Now, when you initiate the pushback, the tug connects, then waits for you to select the direction you want to push, so you can get a chance to get that from the controller. Once you get it from the controller, you select it in GSX, and off you go. That said, as with anything involving code, these things take time and are not as simple as they look.
