Prove that most people WANT Cortana and don't use Microsoft limited metrics like 'number of systems sold'............
And why are you defending Microsoft so hard?
People want personal assistants, the proof is in the millions of echo, dot, and google home units sold.
Google is by far the most powerful of the PA's. Alexa is second. Both are adept at retrieving media and controlling devices.
Siri and Cortana lag these other two due to simply not investing in the infrastructure behind them.
People in general like having a personal assistant. This puts market pressure on Microsoft to provide one. The reality is the Microsoft already lost this battle. What they offer is substantially inferior to Google. But MS is still compelled to throw their hat in the ring. Frankly, if I ask Cortana to play a song or find a video, it does it. If I tell Cortana to pull up pictures of my dog, it fails - Google succeeds at that task.
I'm hardly defending MS, I'm just not bashing them for no reason.
Windows 10 is a great OS; fast and stable. For gaming it is the best one MS has ever produced, allowing DX12 to control resources directly, bypassing OS calls.