These old bands will not have a legacy to destroy when the last person who remembers who they were dies. I think it is a little like “ publicity”— they say all publicity is good publicity . If one new person takes the time to compare the real stuff with the fake, maybe that puts off the day of reckoning for a while.
Getting old has its downsides...
Generally I’d agree, but Zep and Floyd will outlive their members. I’m not a super fan of either, but their contribution to Rock music is historical.