[sneak]

The fact that it isn't in the Play store is the problem, not the fact that it's not on my individual tablet.

Sideloading never "easily fix[es]" anything that needs to happen on hundreds of millions of mobile devices owned largely by nontechnical users.

Network effect, remember?

[anoncow]

That is true. I think whatsapp is trying to avoid confusing SIM-less users , but in the bargain is missing out on potential users, who might want to use whatsapp on their tablet rather than their cellphone.