Further to your point, it has historically been hard to find any commercial software that converts a DVD to a digital file (so it's not just Apple).
The reason for this is that under US law (DMCA I believe) it is illegal to circumvent DRM, a DVD has a very basic DRM scheme. So, commercial companies avoided this area. While any programmers that saw a market opportunity and built something soon wound up removing the key DVD ripping feature of their software, likely a result from receiving a kind letter from a MPAA lawyer.