And then there are 100s of other stories like this one where people catastrophically fail.
* app received press before quitting job
* app started making revenue before quitting job
* author had time to watch the app's trajectory before quitting job
* author diversifies and helps other people make successful apps, across a variety of categories, rather than betting it all on games.
The point of reading success and failure stories is to contrast them as well as feel inspiration or schaudenfreude as indicated.
Too many people think of "app" as "business;" he saw early on that he would need lots of apps (both his and others') to build a business.