I often see people complain about this but I seriously don't understand. The shebang at the top of a bash script will point to bash no matter what your shell is.

At various jobs I've often seen bash scripts to set up your environment (mostly environment variables). Running a bash script with shebang will not preserve the changes to the environment variables, will it? At least that was my experience.

I use xonsh and fortunately it has source-bash for stuff like that.