An inevitable outcome...
... of accumulating technical debt and political in-fighting within Microsoft.
A story: some years ago I was working for a consulting firm that was helping a healthcare company do a Microsoft Dynamics CRM rollout (note: I'm not a Dynamics CRM guy, my role on this was limited to getting some data out of the company's existing customer database into some custom fields in the thing). The Dynamics CRM instance was in the cloud which meant a federated Azure ActiveDirectory setup so single sign-on worked; also, because the company's Exchange servers were still on-premises and Dynamics CRM offers a facility where incoming emails are scraped for potential leads, this involved some complex orchestration between all the moving parts, but Microsoft even offered a little piece of "gateway" software specifically for this use-case to route your mails back out of your on-premises Exchange server to the cloud. Simples, right? Every single piece of the puzzle (Exchange, ActiveDirectory, Dynamics CRM, Azure, the little "gateway" thing whose name I forget) was made and supported by Microsoft. What could go wrong?
Reader, it was like pulling teeth. It was as brittle as hell. The little "gateway" had no documentation to speak with and was obviously some stopgap tool some poor Microsoft bod had cooked up under duress. Thanks to the political siloing within Microsoft, its failure to work was of course Someone Else's Problem™ whoever you happened to be speaking to at the time. It was hinted the problem might go away if you just moved your Exchange servers along with the rest of your IT infrastructure into Azure, Access or American Express that'll do nicely sir or ma'am hem hem. At one point, it all started to work and then the IT guys in the company pushed a Group Policy update that made it sulk for two days until it sprang into life again. Don't ask me what they did, maybe they sacrificed a goat or something.
This is Microsoft in microcosm. They often get stick for building monolithic products (look how long it took, for example, for the "WinMin" initiative to deliver a Windows kernel that could boot without the GUI) in their desire to suck you into having to cross-licence their stuff but under the surface it's a mess of sullen little fiefdoms who barely talk to one another because That Lot Over There took all the nice sodas out of our team fridge ten years ago (people who've worked in Microsoft know this isn't a joke) and We're Never Speaking To Them Again. Even the FOSS people when they aren't examining each others' backsides for who has the most truly open orifice co-operate more. People who want to change things for the better get bogged down in the politics and the organisational morass, like this rant that went viral a few years ago about the organisational inertia that paralysed what should have been a relatively trivial element in the Windows UI.