In rock, some acts age gracefully and others, not so much.
I'll reserve judgment for Mason because it was never really my cup of joe, but I will say that there is something honorable, okay about changing with the times as well.
Pearl Jam's newest tune (I can't stand it), is very poppy, almost happy, kind of radio friendly. Does it make Pearl Jam any less artistically relevant if people latch on to the new sound and enjoy it, no, not at all, but for me, I just don't care for it, and I used to be a big fan. U2 is a band that has enjoyed a bit of a strange maturation curve. U2 started as the post punk, new wave of pissed off youth, I was there, a young U2 could inspire you to action, then, they got rich as hell, and on a personal level they had so little to be internally angry about, so they made records that were different in their core theme, and everybody said "sell outs!", but the reality was that things had changed, and they would rather change than fake it. Were they as good? Meh, though I did see them on the Elevation tour shortly after 09/11 2001 and I will say there was a moment in that show that emotionally griped me in a way that was very genuine.
I guess what I am saying is this. If your up there and being in the moment, being genuine with people, the audience will get that vibe and run with it. If your 40 and just pretending to be 20 you can't really fake it. If you are 40 and you still feel 20 deep inside, you can channel that energy and the audience will buy into it.
A few weeks ago there was panic amongst Rolling Stones fans that Charlie Watts may have informally called it quits. Imagine a 68 year old man that just wants to retire. He has not officially announced that he has, but if he does I say good for him, you can only be a Rolling Stone for so long.
Neil Young has embraced so many changes over his career. In fact, Neil Young is the quintessential ever changing artist. From rockabilly to folk to country to grunge rock to commercial pop rock back to folk back to country, he has done it all. When Young followed Freedom which was primarily noted for his return to crazy horse style grunge with Rockin in the Free World, some people did not understand the shift back to a more introspective country folk sound of Harvent Moon, what was amazing, is that Young does what he feels like doing, on his terms, without clinging to any specific image, now that is being a rebel.