Why should it not be all those same things, except also a stablecoin, so that the price can't fluctuate and the owners/speculators can't make massive profits off of manipulation, exploitation of others' manipulation, and social dynamics?
The goal is to transmit money through a mobile messaging app. If the MobileCoin wants to take donations to support the platform, or even wants to take a tiny cut of each transaction, that seems fine. But I see no justification for their platform to be based around a volatile speculative asset which generally serves no purpose but to create a new gambling market and enrich the founders.
A mobile-friendly alternative to Monero seems like a really cool, valuable idea. But I don't think it's acceptable that it's both a volatile security to speculate on and the payment system for a supposedly non-profit privacy-and-freedom-oriented messaging app.
The problem isn't cryptocurrency; it's penny stocks and all the zero-sum bullshit that comes with them. You don't have to make your new cryptocurrency a penny stock if you don't want to. Here, it seems they probably want to.