Yes, that is indeed the case. Much of what Scrivener does on the Mac is provided for by the operating system—such as integrated spelling and grammar checking (which is so pervasive it even happens in browser search fields) system-wide auto-completion and symbol substitution (smart quotes, etc.), text to speech and speech to text, 99% of the rich text editing features in the software are just from OS X, high quality typography, and advanced font rendering, high quality PDF output from any program, etc etc. Not all of these things may be needed by everyone, for sure, but they are just there, which means programmers on the Mac can focus on providing features above and beyond the basics and can provide advanced features like grammar checking or high-quality text to speech synthesis, that would otherwise be impossible for any single shareware developer to implement.
Part of why the Windows version must proceed at a slower pace is because they are having to re-invent features from scratch. The Windows project is much, much bigger than most people realise. It’s a mammoth project. We want to do it, and we are thrilled to be able to provide Scrivener to people on the PC as well as Linux, but it’s a big thankless job most of the time.
I don’t mean to portray it as all roses over here. There are definitely issues with the Mac, such as the fact that they’ve largely abandoned development on the text engine. It has bugs from 2005 and sometimes it seems like Apple does not have anyone left that understands how the text engine is put together. They’ve become increasingly focussed on shallow, trendy features like Facebook widgets and bad re-inventions of virtual desktops or whatever variety of cheap-to-code features they can trot about once a year to sell their download-only OS updates. There is evidence that OS X’s development has been siphoned off to their telephone division. There are problems on the Mac right now. Don’t jump over here thinking it’s the answer to everything. On the other hand Windows isn’t exactly headed in a good direction either, with the latest OS seemingly more optimised for their quasi-computer tablet than the millions of workstations that made them rich. Yeah, most of the woes facing Mac development these days are common to OS development in general in the industry, as the “common person” discovers they don’t need a full workstation to check their e-mail and do the occasional budget on a spreadsheet. They can do this with a tablet just fine. That will continue to leave workstation users with fewer resources from the corporations that exist primarily just to make money (Apple & Microsoft: equally guilty). Apple wants to see a future where most people buy “apps” for their appliances, and you will see evidence of that in their latest OS versions, not to mention the focus and direction of the company as a whole.
But, we are in that twilight era right now, and in that twilight we can still see the day from when Mac development was innovative, feverish and had great promise for the future. That’s all kind of stagnated, buried under the obligation of supporting every other platform under the sun, but like I say, for a little while now, you can still benefit from the golden age, and it was enough of one that it is still worth consideration, even if the future may not be (and hey, maybe it will be, we don’t know for sure).