How is showing your link speed more useful than showing your actual speed? The link speed does not show anything useful, besides that you might be connected to a router from the 90s.
That menu offers more that you know, apparently. But no one is forcing you to use it. You are welcome to use either :)
Instead of repeatedly claiming it is more useful, you might want to go into detail about what it offers and how it is useful. I don't have a Mac around, but according to the other commenters it doesn't seem to display much more than the link speed, which doesn't sound too useful to me either.