Yes, he considers himself "one of the creators of Minecraft". Because he is one of the creators of Minecraft; he created a part of the game. He doesn't consider himself "the creator of Minecraft", as you claimed.

You can think he puts down regular employees and makes himself seem more important than is warranted. You may think his contribution is tiny compared to the contribution of people who marketed the game or made the website. I may even agree. But that's not what I take issue with. I take issue with you misrepresenting his words by claiming he thinks he's "the creator of Minecraft", which is completely unfair.