Yes, there are machines that can do as good a job as humans, but interestingly they do a better job with lighter squirrelier rims. That's because the machines focus on alignment not tension. The best machine systems (when set up and used well) produce an even tensioned wheel using a tensioning machine separate from the actual truing machine. Then the final touchup and true machine finishes the job. The problem with stiff rims is that they're rigid enough to stay aligned across a slightly slack or tight spoke so the touchup robot doesn't see the uneven tension (neither do many human builders).