I disagree. It makes a ton of sense when proving transactions are legit. So if your game has a lot of high value transactions (think EVE Online), it could make a lot of sense as a way to audit the game servers.
I'm interested in big online games without a reliance on a central server. If all of your trades are handled outside of the game's servers, and the game server logic isn't complicated (or made freely available, like Minecraft), the developer ending support for your favorite multiplayer game wouldn't matter all that much because you could host your own server and keep playing with all the same stuff you had before.
That said, I haven't seen a single game use blockchain properly, and I've only seen a few where I think it could add value. So I'm with Sega, don't add it unless it's the best way to solve a real problem. It's a bad choice most of the time, but that doesn't mean it's a bad choice all of the time.