I'm not sure why most people would even want these features, almost everyone has either an Android phone or a iPhone to be their personal organizer already. We don't need our PCs doing the same things as well.
Windows 10 runs on things other than a conventional giant tower PC. Like tablets and hybrid devices. Would it make sense if Apple only had Siri on iPhone but not iPad? Why NOT have it available on all Win10 devices? You can set stuff up with Cortana to remind you of something while you're doing something on your Win10 device, and have it go with you on your smartphone - Cortana is multiplatform.
I'm still waiting anxiously for a much needed feature: an off button
You can already disable it.