Have Guns N’ Roses become a nostalgia act? Metallica guitarist Kirk Hammett thinks so and he believes the current state of GN’R is “kind of sad.”

Axl Rose, Slash and Duff McKagan reunited this year to embark on one of rock’s most gigantic tours. Over a million tickets were sold in North America alone, with almost a $117 million gross coming in from just 25 performances. GN’R are now gigging throughout South America and outlets report the "Not in This Lifetime" dates will continue worldwide well into 2017.

Though Guns’ tour celebrated the partial return of the Appetite for Destruction and Use Your Illusion lineups, the iconic rock band actually played three-to-four Chinese Democracy songs each night. Guns N’ Roses’ sixth album came out in 2008, the same year Metallica’s Death Magnetic was unleashed. And though Metallica are currently jamming a few tracks from their upcoming Hardwired… to Self-Destruct album, almost none of the thrash legends’ 21st century material has been performed live in the last couple of years.

In a new interview with the LA Times, Kirk Hammett spoke about Guns N’ Roses’ reunion tour. “Unfortunately, they’ve turned into somewhat of a nostalgia act, which to me is kind of sad,” Hammett said. As for the importance of writing new material, James Hetfield shared, “I don’t want to think we’re trying to stay young by writing new stuff, but it makes us feel relevant. It makes us feel like we’re still progressing.”

Metallica’s Hardwired… to Self-Destruct will come out Nov. 18 via Blackened Recordings.

See Kirk Hammett in the Top 66 Hard Rock + Metal Guitarists of All Time

10 Unforgettable Kirk Hammett Moments