The idea of cost vs value. But when you think about it, mining bitcoin 12 years ago was basically easy as well. Anyone, and I mean anyone, can mine it. Tools are cheap and any pc/laptop can mine it during that time. Of course it is quite different now. But the idea of mobile mining should be reducing resources to generate decentralized ownership.
And yes I agree that even though such mobile mining will exist, the market is not ready.
It still does not disclose the fact that just because any brand new project still can be achieved easily it guarantees future worthiness. What does those two coin offer, what things that those brand new cryptocurrencies solve? let's not talk about the market acceptance, rather does any users truly utilizing what those cryptocurrencies offer? if yes the market will follow.
And there is a whole other aspect in regard to decentralization and security, this brand new platform is in its infancy, surely we shouldn't talk too much about decentralization. While in the other hand, the security of a cryptocurrency system might tightly be related to its decentralization, nevertheless, if by chance of this mobile mining does not produce a firm consensus and wholly contributed to the network, it does not mean a thing.