Android Exchange Account Doesn't Sync All Outlook.com Calendars

Running an LG G4 on Android 5.1.  You can sync your Outlook.com Email, Contacts, and Calendars by create a new Account in Settings with Type 'Exchange' it will usually auto-detect and do all the setup for you just by entering your Outlook.com login info (your Microsoft account.)

I've found something very strange though.  If you go into the stock Calendar app, it does not list any calendars other than the primary account calendar for your Outlook.com account.  However, if you use any other calendar app including the "Google Calendar" app, aCalendar, Pure Calendar widget, you name it, you these apps DO list all your calendars that you have on Outlook.com, HOWEVER, it appears Android's Exchange sync does not download events from any other calendar other the primary calendar associated with the Outlook.com account.

This makes no sense as why list the calendars if you aren't going to show the events? 

Of course Microsoft recommends downloading the Microsoft Outlook app which does show events from all the calendars BUT, that app only provides the ability to sync your Outlook.com contacts with the phone, making them accessible to any apps that need to read your contacts.  It does not (like the old Outlook.com app did) sync email or calendar events so you can see them in any other apps.

So what I'm curious about is the issue with the Exchange Account Sync in Android not syncing events from additional Outlook.com calendars a bug in the Operating System, or an intentional limitation or unintential bug in Outlook.com's Exchange Server emulation?

Because I need to see events from all my calendars elsewhere in my system such as on calendar widgets (Pure Calendar Widget) my workaround it to use the Gsyncit plugin for Microsoft Outlook Office Desktop client which does bidirectional syncing between Outlook.com and Gmail so it allows you to maintain contacts and email in both Outlook.com and Gmail accounts and of course all the calendars sync properly when using Gmail (Google) as the calendar source.  The big drawback of this though is that if your PC isn't on, any updates to your Outlook calendar will not get synced to your Gmail calendar/contacts.  Of course the better solution would be to make Gmail/Google your primary place for managing your contacts and calendars however I share a lot of my calendars and I've found your average user finds the Outlook.com interface more user-friendly (and cleaner) than the Gmail interface and more importantly the Outlook.com account will sync more seamlessly with Windows which is what the majority of people use for their desktop operating system.

I'd love to find out if Microsoft (Outlook.com) or Google (Android) is responsible for the lack of full Outlook.com to Android Calendar sync support and if it's intentional or a bug?