Something to think about, or maybe not. Not all objects have to be right in every way.
Plan symbol
Plan symbol on remote stories
3D hidden line
3D shaded
3D render
Elevation
Elevation in distant area
Section
Polygon efficiency
Scale sensitivity; which compounds the plan symbol, section, and polygon issues
Listing
Labeling
User interface
Parameter list
Parameter transfer management (Unique parameters)
2D graphical editing
3D graphical editing
Selectability
Code maintainability
Intra-library consistency
A frequently used, complicated, widely viewable object, such as a window, needs to be right in virtually every way.
The development environment gives very poor support for many of these requirements. As Archicad adds features, items are added to this list. Irritatingly, the environment has not kept up, and is way overdue for a tear-down. There is no section window, no remote stories, no graphical editing. The full features of the current GDL architecture are not supported, so we can't even imagine modern development features such as syntax coloring and auto-completion.
One of those things that bothers some people more than others.