As recently noted in the build documentation, compiling it yourself is not recommended for most people. (First, the result will be much less efficient than the official binary unless you tweak things for your particular compiler. Second, there is the chance of running into compiler bugs and bugs in Mini vMac that show up only on some compilers - the official binaries are much better tested.)
One of these is gratis and libre, and the other isn't. If you want to stand on that side with Windows and expect other people to help you out, then what you're asking for is for them to shell out money and a lot of effort for you. Whereas the reverse is not true; in comparison, the picture of a Windows user having to get access to a FOSS toolchain for themselves looks trivial—and with the abundance of ready-made system images that you can spin up without even having to reboot your computer, it is.
"Windows user" is not an ADA-protected class.
I use it daily and test and compile my programs on both Windows and Linux.
On the other hand I also stay away from projects that don't use cross-platform build-systems like Ninja, or CMake. Shell scripts are sometimes incompatible even between different distributions and shells.
The worst offender (that I know of) by far is GNU Octave. On Windows they basically ship a snapshot of a Linux dev box (complete with the whole directory tree, compiler suite and everything) with userland binaries compiled for Windows. So much for being "cross-platform"...
also:
./setup_t -t xl64 >setup.sh Unknown value for -t
attention to details indeed.
[edit]: I assume this'll only work on a Mac. Too bad, looked fun.