I'm certainly not profitable--a game like Courier takes some time. However, I simply would not be able to create it in any other engine. I really don't have the time to improve my C# skills to a high enough level to do what I can do so rapidly in C2. It would also take longer for me to type it all out. Then, I build my levels out of multiple objects in the C2 IDE (the game is NOT tile-based). This would be a nightmare in Unity and would likely end up with me having to do a lot more 3D stuff than I'm interested in doing. C2's time-saving nature is essential to Courier ever happening. I can't predict the future, so it would be irresponsible of me to hire a team (even a second person would essentially double the profit margin needed to net any gain). And, other than Game Maker, which I've played with and really don't enjoy using, there is nothing else like C2 that both allows me to do some higher-level stuff AND allows such rapid development.
So I really do think Courier will be profitable when it is completed (next year), but it simply wouldn't happen with any other tool.