So your point is that founder happiness is directly related to the startup's chance of success, which seems questionable, but possibly true. Then you define hap

So your point is that founder happiness is directly related to the startup's chance of success, which seems questionable, but possibly true. Then you define happiness as things that are good choices for the business. Of course doing things that are good for the business are good for the business. This is a bit of a circular definition. That said, choice of programming language is important. It's possible to be 10x to 100x more productive in one language (at least to start with), if it has libraries (included in the standard lib or community) that do most of the hard work for you. It's very easy to get started with a Python project, if your work at all uses Numpy/Scipy/ETC. The choice of programing language also is a big factor in what engineers you can hire in the future.