I get where you're coming from about Axl's age, but I think it's important to consider why people bring it up.
Many fans are frustrated because there hasn't been much new music for over 20 years, and there's a perception that Axl has spent a lot of time blaming others for these delays. It's not just about his age. For instance, look at Bob Dylan. He released ten critically acclaimed albums after turning 60, including 'Modern Times,' which topped the charts when he was 65! So age really can be just a number when it comes to creativity and productivity.
I would have been completely at peace if Axl had announced back in 2008, that he was done making new music and just wanted to do nostalgia tours. It would have set clear expectations. Unfortunately, he’s kept fans in limbo by occasionally mentioning in various forums and interviews, like the China Exchange, that he has stuff under his sleeve and entertaining some ideas with members, giving hints and so on. This has understandably led to such opinions among fans who are left expecting more. Not to mention Nando's mockery of music hungry fans.