I'm still on the fence about Medium. Despite having an account there and no stories posted I still get people following me.
Sure I get what Medium is trying to achieve by making blogging easy for everyone but I'm still on the fence about such a high volume of people using one platform.
Mark Lowenstein highlights a few of the benefits and drawbacks with Medium.
Medium offers very little in the way of guidance or tutorials to help one get discovered. There is nobody one can talk to, unless you’re an established brand or company who wants Medium to host your content. I’d bet many writers would be willing to pay a modest fee, or sign up for a premium membership with Medium, for some help building an audience/following and getting their content discovered.
Discoverability is a problem many people face on Medium but I don't think this a problem with Medium directly.
When you start writing on Medium, you're writing with (and against) thousands of other people. That's a lot of competition, so why not blog elsewhere? It's your decision.