Improve integration of Linux tools with Windows command line

It seems to be impossible to execute Linux tools from cmd or anywhere else outside bash.exe.

For example, I can't run grep from cmd:

C:\>C:\Users\test\AppData\Local\lxss\rootfs\bin\grep
'C:\Users\test\AppData\Local\lxss\rootfs\bin\grep' is not recognized as an internal or 
external command, operable program or batch file.

C:\>C:\Users\test\AppData\Local\lxss\rootfs\bin\grep.
'C:\Users\test\AppData\Local\lxss\rootfs\bin\grep.' is not recognized as an internal or 
external command, operable program or batch file.

If I give grep the .exe extension, it still doesn't work:

C:\>bash -c "sudo cp /bin/grep /bin/grep.exe"

C:\>C:\Users\test\AppData\Local\lxss\rootfs\bin\grep
This version of C:\Users\test\AppData\Local\lxss\rootfs\bin\grep.exe is not compatible with
the version of Windows you're running. Check your computer's system information and then
contact the software publisher.

It would have been great to be able to use Linux tools directly from Windows scripts. Otherwise I am kind of forced to keep cyg *cough* win installed.

Maybe automatically give executable ELF files an .exe extension and/or have the Windows subsystem recognize them and forward to Lxss?

Start by reproducing the reported commands from Windows cmd and bash.exe, using the /bin/grep example and the attempted grep.exe invocation. Determine how executable Linux tools are currently handled outside bash.exe; done means Linux tools can be invoked directly from Windows command-line scripts without the compatibility error.