Why some of the ramps are not operable

[ATC]

And these ramps on the second picture is it used for GA or whatsoever?

[Jamesonplanes]

Im not sure what the reason behind it is. But I imagine its too hard for the devs to make them useable.
Please correct me if im wrong!

[carlsberg72]

Usually GA related so they are there for decoration rather than usage unless the devs decide to put GA aircraft in the game. Which I think is a very low priority