The problem of them not being as good at creating a new programming language as they want to be. So many amazing projects started as someone scratching an itch

The problem of them not being as good at creating a new programming language as they want to be. So many amazing projects started as someone scratching an itch, often completely unrelated to the eventual product. And even if a project doesn't take off, if the goal was to get better at programming (and not marketing, project management, etc) it may be still be a success. Both forms of projecting have value. It all depends on personalities and where people are in their careers.