Linus is the one who got a workable thing out in the public's hands. He didn't even want to name it Linux, but someone came up with that name and it stuck.

The GNU project did a lot of great things, but ultimately they weren't able to get a full-fledged operating system out that people could use, so they lost the opportunity to name it. It really shouldn't matter to them though. GNU is well known, its philosophies are critical to how the free software and open source communities work, it was basically a massive success in the way almost no other volunteer non-commercial projects ever are.

But tagging "GNU/" in front of Linux is dumb.