At the moment, people with Bitcoin who want to buy Steem need to go to one of the external exchanges like Bittrex. That's a whole extra step that doesn't need to exist. The internal Steem to Steem Dollar exchange works, and has no fees. I suggest expanding the internal exchange to also support Bitcoin to Steem trading on steemit.com. By reducing the barrier to entry, more users are likely to purchase Steem, which benefits the entire Steem community.
I'm not sure what is the best way to build this functionality from a technical and legal point of view, but I'm sure if there is a demand for it, devs can find a way. What do people think?