But merely looking at what Notch has done, it looks to me like he got lucky rather than having some vast talent for making fun games.
At the top is the idea that if you make a game fun enough it will take off like Minecraft, but virality is not simply a product of fun, there are so many intangibles that go into blockbuster successes, and the people who get really good at wrangling those elements and distilling out a formula are not renowned for their talent (eg. Hollywood blockbusters).
But unpacking further, talent is something that needs to be developed. Natural talent is nothing without practice upon practice. Talent in some area requires years of practice that laymen will never really understand or appreciate. We can all talk casually about various kinds of talent, in programming, in art, in game design, in music, etc, but any kind of serious discussion needs to touch on the nuances of the specific work they are doing. Claiming Nickelback is more talented than Arcade Fire because they've sold more albums is a sure way to kill a conversation about music.
My problem is simple: you define talent as being "successful" by your opening sentence. From the beginning you question his talent because you haven't seen more successes from him. That's what I'm taking issue with.
Of course I don't want you to define other things needed for success, that's precisely the problem. Success is not a barometer for success, more like a very very loose correlation.
I question his talent because I haven't seen anything interesting from him since Minecraft. If he had produced something great that nobody bought, I wouldn't be saying what I'm saying. But he hasn't made anything of interest.
People like notch and other indie developpers are looking for things beyond immediate technical prowess or easy instant fun. They are after something you may call poetry, and how to explore new opportunities created by technology.
In this regard and judging by the large interest of children for minecraft, this man is talented.