Why doesn't Apple incorporate professional graphics cards in their computers?

Traditionally a Quadro FX gave you very high view port performance in 3D digital content creation, CAD or CAM applications; and were more stable and provided more accuracy. This was achieved through driver optimisation and by working closely with the software company development teams. That all still stands, but now performance improvements can be found in some video and image editing applications. The Quadro NVS cards are typically for stability, accuracy and lots of displays rather than performance. You also know that these cards are certified to work with certain applications and you can expect a better level of support - plenty of stories of Quadro users getting Nvidia engineers to send them driver tweaks within a working day for a problem specific to their application for example.

You don't need a special graphics card to get all that with a Mac because Apple are in control of it all. In addition to that, the vast majority of customers who want/need professional cards aren't going to be Mac customers any way. The professional Mac users tend mostly to be working in video, audio, graphic art or photography and these areas, as I mentioned above, haven't benefited from Quadro cards (or Fire GL/Fire Pro).

Or in short: because it wouldn't make them any real money.

Quadro and Geforce are 2 different line of cards for 2 different purposes.

Geforce is ment for gaming, and ordinary applications to watch movies, or special efffects used by the operating system.

Quadro on the other hand is ment for professional 3D artists, or people who work with hi-funda physics problems which may be in designing a bridge and working on stress levels of various parts of it. Or airplane designers to model the turbulence around various segments. These require a much more powerful card in different areas. While geforce is more tuned to the gamer.

As why they stopped the line? I am sure its available but the demand is light enough where they don't need to publicize it. Those who want such a machine would request it directly from Mac.

well i have a macbook pro, and i am running the intel HD graphics card. apple does this for one reason really, everything they put in their computers has to work with their computers, just because its not a TOP OF THE LINE graphics card, doesn't mean it doesn't kick some ***. it is built to run beautifully on the mac, unlike on windows computers