It's not necessarily just business strategy at this point, though.

Microsoft made a concerted effort to have the apps be truly cross platform back in the 90s. In this video, folks from the Office team explain how they engineered the code to work for Mac and Windows. And while Win Word 6.0 had great sales, Mac Word 6.0 did not. Mac users didn't like having a Windows-like app on their Mac, there were Mac-specific bugs, etc.

So at the time, the company decided it made sense to develop the apps independently for each platform. Around 12m in the video linked above, Igor mentions that Mac Office 98 was did much better in the market after being developed separately.

Then, in the mid-late 90s, Windows took over the market. It makes complete sense for a business to dedicate resources on efforts where the largest number of customers are, and that was Windows. This began the Windows-Office relationship that gave Microsoft a dominant market position for years.

Fast-forward about a decade. Microsoft continues to invest heavily in Office for Windows due to its overwhelming market share compared to Mac. But they miss mobile resting on the laurels of past achievements. At first, Microsoft thinks it's not a big deal. Steve Ballmer laughs when asked about the iPhone, saying nobody would pay $500 for a phone. But then mobile doesn't go away, customers start buying products running non-Windows software, and there's an inkling of fear. The company scrambles to maintain its position as a market leader, attempting to trumpet Office that is "1st and best on Windows".

Ultimately, they admit defeat. Cross-platform is important now. People want the same experience regardless of their device/platform. Microsoft releases Office for iPad, then for iPhone, Android, etc. They're serious about being cross-platform.

But remember that decision back in 97-98 where the Mac version started being developed independently? That's almost 20 years of software changes and people want it all on whatever device they're using, and they want it now. Paying down technical debt is not easy, especially when you consider Office is some of the oldest yet most widely used software on the planet. So they prioritize what features it seems most people need, and they keep cutting away from the top. They even start making an effort to converge the codebases that diverged decades ago. But it'll take time. And even today, the market share for Mac pales in comparison to Windows, so it doesn't make financial sense to invest in it too heavily.

I'm interested to see how the next couple of years play out. Microsoft promises continuous updates for Office. The iOS and Android apps are receiving updates monthly, the "universal Windows" (PC and phone) apps are coming, and any number of other things happening we don't even know about yet.