I don't understand why more languages don't just handle a separate data stack from the call stack. Then the call stack can remain harder to screw up and you can

I don't understand why more languages don't just handle a separate data stack from the call stack. Then the call stack can remain harder to screw up and you can continue using stack frames for arguments or locals as desired. When feeling productive (not much in the past year unfortunately) I've been trying to build a bytecode for i86/x64 that operates this way.