[galfarragem]

AutoCAD is still a standard because it is flexible and scales great. You can draw as easily a pcb, a dog house or a city.

Imagine you are starting a concept for an housing block. You are just starting to "shape it". You don't really know if it will be a square or a rectangle or even a more complex polygon. If you use BIM (e.g. Revit), you'll need to define what wall is exactly made of, what kind (and brand!) of window is it, etc, since the beginning.. you don't even know yet what the building will look like! It's completely nonsense and an huge incentive to repetition: you use what you already have in your library once it is a massive hassle to create new objects.

When the project is settled and approved by authorities, then and only then, may pay (depending on the scale) to convert it to BIM: you'll get 3D renderings, bill of quantities and a realtime model of the building out of the box.

An analogy for HNers: Autocad is a text editor (emacs kind), BIM is an IDE.