About Minecraft, it's also easy to forget that while he was alone at the start, and he managed to get people interested in it enough to start give him cash before it was done, it was not until he had the cash to hire a team that he was actually able to finish it.
And afaik he did have help with art and sound already before that.
There are really not that many true "lonewolf" developers out there that are successful these days.
He also had an established community that liked sandbox games from his development of WurmOnline. On his 7 year "stint" on WurmOnline the game developed vocal community that liked crafting and world building, and got "outposts" from other major communities like Something Awful, MMORPG.com, 4Chan... Notch also invested heavily into contest communities like the Java4K contest, and just other random places. Communities and interest that lead to early investment, interest and gameplay feedback on minecraft as he developed it. All which eventually allowed talk to happen about minecraft all over the Internet, which lead to features on news sites like Rock Paper Shotgun and similar.
Minecraft wasn't about burst and boom that most other people have seen. It was about a slow build up to critical mass from a wide assortment of fans, and an obscene amount of community participation by the developer himself, experience the developer learned from a lot of hard work elsewhere.
edit: In other words even with one developer, it was laughably not lone wolf.