To be fair, you are comparing WP to the already so matured OSes like Android or iOS. WP8 was merely 2 years old as it was redeveloped from ground up again after WP7 fails. But within these 2 years, we are now seeing action center, transparency tiles, VPN, etc etc. Just 2 years, we are already having a voice assistance Cortana. But it took Apple to add Siri to iOS only at its 5th iteration. And Google Now was introduced only with Android 4.1 Jelly Bean. Do you not see how fast Windows Phone 8 actually evolved within these 2 years? And what triggered the low to mid end budgeted phone wars? It is Windows Phone too because of its capability to run under low cost devices and still performing very well.
Android is very open. However, it also brings along flaws, performance issues, fragmentation due to so many different OEMs, etc etc. Windows Phone strike somewhere in between. When WP8.1 is out, I bet all WP8 devices will be able to get updated. And this is why iPhone is still so popular as consumers get the updates promptly without the need to beg OEMs to release updates for their older models - especially with big OEMs like Samsung which releases tons of different Android devices each year.
Time is an important factor for an OS to grow. And from what I see, Android has reached its peak. Same goes for iOS. But what's lucky for iOS is that Apple also sells desktop OS, hence they can boost about Continuity with their latest iOS8. On the other hand, Google Chrome never pick up good traction at all. So, Android is just at its peak. Given that MS is also a desktop OS maker and along with its gaming businesses, I'm seeing potential with Windows Phones. More features will come for sure, but you just need to be patient. Rome don't get to build in a day. Just my 2 cents.