But it's not only about the features that are missing, it's also about those that are unique. You will maybe never get a third-party browser, community repositories or a root shell on iOS because apple does not allow you to install it (without jailbreak). For some people the ability to do this things may outweigh the missing elements - every person has different needs, and what's core functionality for person A is never used by person B. I think jolla may never be able to play catch up with the big players but perhaps it's possible to survive in their niche for a small company if there's enough people that value the unique features over the missing ones.

Compared to WP, I personally do not see such strong points in favour of WP, other than that it has a very fluent interface, the 1020's camera and some nice handsets from Nokia. But again, this may be the other way round for anybody else.