Why does calling a nested batch file without prepending “call” to the line exit the parent batch file?

Question

I understand how to call nested batch files from within a parent file using the call command, as there are plenty of resources on that:

• CALL

Answer 1

As Sean Cheshire wrote, it's necessary for backward compatibility.

But starting a batch file from a batch file without using CALL does not terminate the parent!
It looks that way, as the parent normally will not executed further after the second batch exits.
But using a call before starting the second.bat, will show that the first batch isn't terminated.

parent.bat

echo parent.bat
call :myLabel
echo back in parent.bat main
exit /b

:myLabel
second.bat & echo back in parent.bat
exit /b

second.bat

echo second.bat
exit /b

I use here the the secpond.bat & echo back ... to avoid another bug/feature of cmd.exe.
If you use second.bat without any extras it will start second.bat AND jump to the label :myLabel in second.bat!