Microsoft (NASDAQ:MSFT) recently removed 1,500 "misleading apps" from its Windows Store, citing a need for better clarity in naming, categories, and icons.

Microsoft's announcement came shortly after scathing reports on Zdnet and How-To Geek exposed how bad the problem was: fake antivirus products, fake Chrome and Safari browsers, an unofficial Adobe Flash Player, and even a fake Windows 8.1 update had gone unnoticed in the store. Some developers even repackaged free apps as paid ones.

Windows Store. Source: Microsoft

While Apple (NASDAQ:AAPL) and Google (NASDAQ:GOOG) (NASDAQ:GOOGL) have smoked out bad apps in the past, Microsoft's sudden Windows Store purge highlights several noteworthy facts about its Windows apps strategy.

The problem with Windows Store
Microsoft currently has about 170,000 apps in the Windows Store, according to app-tracking service MetroStore Scanner. That makes it smaller than the Windows Phone Store -- which hit 300,000 apps last month -- and an ant compared to Google Play and Apple's App Store, which respectively house 1.3 million and 1.2 million apps.

Windows Store apps are only designed for Windows 8 and RT tablets. According to Net Market Share, about 13% of PC users in the world use Windows 8 or 8.1. But according to research firm Soluto, 61% of desktop, 60% of laptop, and 44% of tablet users launched a Metro app less than once per day.

Windows 8's Metro UI. Source: Microsoft

Simply put, there's no need for apps on Windows 8 PCs when full-featured software can be installed as a desktop application. The only reason to develop a Metro app is to reach RT users, which is being kept on life support by the Surface 2 and Nokia Lumia 2520.

That's why Microsoft introduced cross-platform "universal apps" for Windows, Windows Phone, and the Xbox One in April. That was a step in the right direction toward a "One Windows" ecosystem, but Microsoft dampened its appeal by letting developers charge tiered prices for cross-platform licenses.

Microsoft's mercenary developers
Most developers flock to Android and iOS for a few simple reasons. Developing for Android reaches a huge audience, but hardware and software fragmentation can cause compatibility issues. Developing for iOS reaches a smaller audience, but apps are much easier to test thanks to Apple's homogenous hardware and software ecosystem.

By comparison, Microsoft's Windows and Windows Phone Stores control a poor market share on fragmented hardware. Windows Phones, which are fragmented between low-end devices to high-end ones, only amount for 2.5% of the world's smartphones, according to IDC. Giving developers cross-platform compatibility with Windows devices and Xbox Ones increases the appeal slightly, but not enough to convince most to switch over from iOS and Android.

That's why Microsoft hired a "mercenary army" of developers to create apps for the Windows and Windows Phone Stores. Last May, Microsoft started offering developers $100 per app, which a maximum payment of $2,000 for 10 apps submitted to each store. A month later, Bloomberg Business reported that Microsoft was paying more prolific developers over $100,000 to bring popular apps to Windows Phone.

Source: Wikimedia Commons

Charlie Kindel, a former Windows Phone manager at Microsoft, criticized the strategy as a "bad idea" in a blog post, stating that it was an indication that "Windows is in even more trouble than most of us already believe."

The problem with mercenaries
Tempting developers with guaranteed payments helped increase the size of the Windows and Windows Phone stores, but quantity isn't equivalent to quality. I'm not saying that Microsoft paid for deceptive apps, but the company's strategy of paying for apps likely gave developers the impression that Microsoft was more willing to approve mediocre apps than Apple or Google.

According to a Nielsen study at the end of 2013, mobile users only used an average of 26.8 apps per month. This means that it really doesn't matter if an app store has a thousand apps or a million -- it just had to have the right ones.

But in that department, Windows Store falls short. Apps like Instagram and Vine are missing from the Windows Store, although they have been released on Windows Phone. Well-known mobile games like Candy Crush Saga and Clash of Clans are nowhere to be found. Nothing from Google's ecosystem -- Maps, Drive, or YouTube -- has an official app. These are the gaps that mercenary developers can't fill.

A Foolish look into the future
Looking ahead, Microsoft has to clearly define the line between desktop and mobile devices if it wants Windows 9 to succeed.

Windows 9 won't be unveiled until the end of September, but reports that Microsoft will merge all its devices onto a single OS and turn Metro into an enhanced Start Menu are encouraging. The idea is that all software -- desktop or mobile -- will be downloaded from the Windows Store's walled garden instead of the Internet. If Microsoft sticks to that clear plan, software developers won't care if an app is a desktop or Metro-based one. Like mobile and desktop websites, there will only be one app with two views.

To get there, however, Microsoft has to keep the Windows Store clean. Clearing out all the junk from its app store sends a clear message: Windows Store isn't a lawless land, it's a platform that could eventually replace the dated practice of seeking out and downloading software from the Internet.