Their user interface was a true gem - beautiful yet functional. The devices were incredibly fast, and the optical cursor was a revelation. I genuinely believe the way the trackpad cursor functions on the iPad is inspired by BlackBerry’s design.
They owned their space in their time, nothing came close, and then, one day, times have changed and their product become obsolete. I don't blame them.
It's cool to sit on HN and think everyone should pivot on a yearly basis, but in reality it rarely happens for companies that big. It takes a lot of time and effort to change to course of a tanker ship, and when you're in position that you have a product that is precisely on point, competition can't touch you, the most reasonable thing to do is just not to fuck things up... and then it's too late. Sometimes. Most of the time it's the winning strategy.
If anything, Nokia was distaster.
So it makes sense not to rock the boat.
It would be like trying to write code on an iPhone today.
Android, courtesy of being open source, was just able to move much faster
I think if they had just open sourced the OS, like Android, instead of killing it, Windows Phone could have been a decent Android competitor
Apps availability was the main issue - there were people who baked their own 3rd party apps for instagram, snapchat and vine. Google on the other hand "fought" with MS by blocking access to YT from their app on the devices - because unsurprisingly ads in videos weren't playing on it. Only Opera released their browser for this platform - Mozilla had short lived Fennec in early alphas.
The OS updates were handled by device manufacturers/service providers and release times differ from one company to another. That could be also another issue leading to platform's failure.
Version fragmentation was also another thing; devices running WP7 couldn't upgrade to WP8 - these had a special 7.8 release which bring some features from 8.0. Same thing happen with WP8 devices - the top-most could get W10M while mid and low-end ones would stuck on 8.1. I tried installing 10 on my Lumia 1320 - it made phone ran hot.
Metro interface was perfect on mobile devices and tiles were an amazing middle ground between icons and widgets at that time. Apple pick up quite recently that concept allowing icons to be expanded into widgets serving particular bits of information. Overall the OS interface focused exactly on displaying needed information instead of delivery form for it; this was achieved by big font and modest use of icons within e.g settings pages. Windows 8/.1 failed miserably on desktop as we know - it wouldn't be as bad if start menu and desktop paradigm would remain and only visually system would receive a flat "lifting" as it did with Windows 10. But at that time it was too late.
At the time I was working on WP apps for a customer and needed 3 different OS installed to work on their apps.