Earlier quoted context omitted.
For what its worth, I worked on the InDesign team during the InDesign 2.0 - CS timeframe, and my boss at Adobe had worked for a long time at Quark. He was very knowledgable about Quark's code. During that time period, he repeatedly asserted that Quark would never be able to produce an OS X/Intel version. He believed that there were too many MacOS/PPC specific optimizations, and that the code was so difficult to modif…
As a side note, I always wondered if the Creative Suite product offering (which bundled ID with photoshop) was just hype or also really got people (especially students) to just forget about Quark. That seemed to happen around the same time, give or take some years of overlapp.
The article makes that point explicitly:
And things got even worse for Quark when, in 2003, you
could get InDesign as part of the newly introduced
Creative Suite Bundle, which as a publisher or graphic
designer, you would have probably bought anyway for
Photoshop and Illustrator. You were basically getting
InDesign for free—it was a Trojan horse in the bundle box,
and I think it really sealed the deal for people on the
fence about the switch.