I'm not as invested in CS&N as others here, so this is easy to say...

It's sad that CS&N are over, but time passes. They are all in their 70s now aren't they? It's the time of life when many people in normal occupations will retire and spend their time in their gardens or whatever. Musical artists, actors, and writers often keep on going. And for fans that's good as we get to see new product. But, if they aren't getting on, then perhaps it's time for them to all do their own things and not have to put up with things that they don't want to do any more.