Questions about STEEM

I understand that upvoting and downvoting here gives me STEEM. How is this achieved? Is STEEM made out of nowhere? What if I make a bot and upvote everything on the site? I'm confused.

Furthermore, why aren't there any arch linux AUR packages yet? As an user I would expect there to be some after a few months of it existing. Is it a windows-centric cryptocurrency?

Finally, do you personally think it will grow into something big? Please think about this, as we all have biases.

Thank you!