Close is used in instant apply dialogs since you don't need to confirm/mark changes before. So it would be quite confusing to the user.
@Colpompidou:
Revert resets the state of the system as when the application was started. So we would have to remove applications that have been installed in the meantime ...
Perhaps we should consider changing gnome-app-install into an application.
@Matthew:
Close is used in instant apply dialogs since you don't need to confirm/mark changes before. So it would be quite confusing to the user.
@Colpompidou:
Revert resets the state of the system as when the application was started. So we would have to remove applications that have been installed in the meantime ...
Perhaps we should consider changing gnome-app-install into an application.