Uh yeah. Because that's a Main function, as in the first method that the JVM invokes, except that the main class that the JVM is invoking is GradleStart, calling Main(args) there. Which means YOUR method is not called. Just because it's public and static doesn't mean it gets invoked.
I haven't used the new launcher yet, but I'd guess you already had a profile called "forge" and the installer didn't overwrite it.
What you need to do is create a new profile and select the appropriate Forge version from the versions list.