Of course people should get Steem first before they can pay it to somebody. For now you there are two ways you can get Steems: buy on the exchange or get rewarded on Steemit. It can change in the future, it can be simplified somehow. The smartest people on the planet are working on such technologies to bring it all work for the regular people, they will work it out.
Maybee they will come out with idea that the button on Wordpress blog can be integrated with your Steemit account, from which you can directly pay to Wordpress blogger. Who knows?
that you will directly pay with steem is for sure. But this will only work if Steemit.com is already mainstream. Hope so!