In general I agree with you, but you need to consider that alternative means not something different, but something instead. And if whataspp, facebook is standard in mobile, it would not matter how it's right or wrong or if it should be like that, but that Jolla doesn't really provide that option.
While activity can be utilized as something new and useful (we had it on N9), it would not replace some of the apps, as functionality and all features of those apps are available in app and not as extension in activity.

Mobile era is not something new and most standards, apps and functionality are already defined. I'm not saying that it can be changed, but I'm saying that it can't be ignored.
What I'm trying to say is that they need to reach to the point where other platforms are and start from there. To make changes as improvement or replacement. But currently they introduced a lot of new features that are not used and can't be utilized, just because they miss the common adopted functionality and apps. They need to close the gap in order to be in first line.

As per applications and Jolla future — I'm not sure if they by themselves understand what they are doing and there is any direction. Most of the management folks that said that I'm just hater and do not understand - left Jolla. And we both know that me is not the reason. As per paid apps - this is never ending saga. They raised the issue themselves long time ago, but nothing was done. It seems that they start something, do not finish it and switch to something different and this leads to failure after failure.

In the begining I wanted Jolla to succeed and I was in first wave, but they proved me wrong. And as I do not care if they succeed or not - it's very important that people here would not put them on pedestal just coz they are not android. Especially with "no facts proves".

Jolla had a lot of time to prove themselves. And yes they have updates (no one talks that they slowly releasing less and less and that they promised every month update), they released 1.5 device (0.5 is Jolla C + tablet together :P ). And all this in 4 years or even more.
If someone uses linux as backend doesn't make him linux supporter or lover. Even google use linux in many their projects, as well as FOSS, but less and less people like them.

So what would be the reason for Jolla except "it's not android or iOS" as it's not the argument. When I want to choose something good I go - why i like it, and not why I don't like else.
P.S. I just though how funny it would be if someone would say as his/her marriage vow:
"I marry you because you are not X or Y, as they are shitty people, that's why I choose you"