Just installed Xming, "apt install xfce4-terminal".

DISPLAY=:0.0 xfce4-terminal &

After that, it about 90% of typical Unix setup with all the control key bindings for copy-paste, etc.

I wish WSL 's bash environment can run windows programs/utilities like Cygnus.

I think you mean conhost (cmd is the shell program, not the terminal). It does have it's rough edges but it's much improved from where it was only a few years ago and its far from the only way to host a WSL session. This includes support for ANSI escape codes (TERM=xterm works fine) and better colors (though you may need to reset the defaults if you're upgrading from an old system). Lastly, there are plenty of other terminal apps which make this much more familiar for folks who prefer things like tabbed windows, or theming.

A second point, WSL programs don't rely on an active conhost shell to keep running. You can kick them off and run them in the background just fine. On one of my machines, I have a full i3 session running with no conhost window in sight. Everything works seamlessly, I can talk to my editor running as a Windows app, cut & paste back and forth, see file change notifications, hook up my docker command with my docker for windows VM, and so on. It's nice enough that I miss it when on my Mac and get annoyed with some of the fussy application alternatives on the typical Linux desktop.

Correct me if I am wrong, but it doesn't have to be inside cmd. A lot of people use cmder/conemu, and it works great with WSL. You can even put your own shell on top of WSL (zsh, fish, etc.), if you are inclined to do so.