Microsoft and Consistently

[aerosidinc]

Guys I just cant understand that why cant Microsoft havr consistent design across all? Ok I am not going to talk about windows 10 and UWP apps coz I think their Microsft design language is already mess. Lets just look at Microsoft apps for android. Why does every app uses different ui elements than other. Why doesn't all app simply follow Material Design? For example why does Onenote, word, excel, ppt app has rectangle background but not outlook app(and outlook app is the only app that strictly follows Material Design on android), some apps has wireframe icons like onedrive, some apps have own icon like Skype, each and every app has differently designed splash screen. Outlook has different loading icon, skype has wire like loading icon, office app have different laoding icon, xbox app has different one. Similarly, bing has different design ( somewhere it uses shadows and layers whereas somewhere it uses flat).Why? Why can't Microsft just design one universal design like Google does? For eg. We know if googlr uses splash screen for apps all of them will be consistent. Another thing is how google has made the top google bar and app drawer so universal and consistent in its web services. Whether u r on gmail or youtube or docs or any website there is consistent bar at the top. Why can't MS think like this? Can anyone provide actual reason behind this?