I have never asked or cared what grades anyone ever got. I don't think that there is any correlation between grades and real world performance. I am in the software engineering space though and I think that there is a lot of room for creativity. Having rigor in academic engineering isn't always useful and I've found actually prevents you from getting things to the good enough stage.

I totally agree that "determining a good hire requires multivariate". Maybe grades are a proxy for other meta skills, but I think evaluating those skills directly are a better indicator.