If you write your code in Python, many team members or new hires will already know Python and hence be able to dive right in to the code base.
If you write your code in Hy, many people are going to have no idea. Small chance they already know it. A minority of people will have some background in Lisp, and if you already know both Python and another Lisp, learning Hy should be straightforward. But for a Lisp-naive developer, it is a big speed bump.
Also there is a lot of existing tooling around Python code – static analysis, etc – which might not be able to handle Hy. Sure, it can process the transpiled Python, but that produces a lot less pleasant experience for the developer. You really want native Hy tools, which are going to be behind native Python tools.
If you write your code in Hy, many people are going to have no idea. Small chance they already know it. A minority of people will have some background in Lisp, and if you already know both Python and another Lisp, learning Hy should be straightforward. But for a Lisp-naive developer, it is a big speed bump.
Also there is a lot of existing tooling around Python code – static analysis, etc – which might not be able to handle Hy. Sure, it can process the transpiled Python, but that produces a lot less pleasant experience for the developer. You really want native Hy tools, which are going to be behind native Python tools.