> Surely the things you value are worth hanging on to/fighting for?

Maybe. For me at least, the art is in what you choose to value in different contexts, rather than in absolute terms. Thinking about this specific case, I might value my own peace of mind, money, and time much more highly than justice or retribution.

Other times, something we value is taken from us and living in the past, spending our days wishing for it, etc. can prevent us from "moving on". It can become an anchor or baggage.

The cultures I'm aware of that practice meditation value letting go of the things that keep you attached to physical existence, because they're looking forward to a spiritual existence that value more highly.

For my part, I feel that there's value in critically examining parts of your life and deciding what really matters. If something matters, fight for it. If it turns out something didn't, or it doesn't any more, let it go so you can make room in your life for more important things.