OK, here's my take on it.
People try to intuit what others would like and very often miss the mark because they project at least a part of themselves into it. So, your dad clearly knows you well enough to know you love fishing, so he started there. Kudos to him. At least he didn't give you a Tiffany lamp.
He probably thought "fishing.. he has enough poles and lures. Gee, here's this awesome gadget that tracks lunar cycles. Lunar = nature, natural. [subconsious says: I love cool gadgets] This is a really neat, useful natural gadget! He'll love it! I hope he does!"
As for being sad that people try to connect with material objects, didn't the Indians give material things--food, fur, etc.? I think this is not a American Consumer issue. This is just how people are. They want to connect, they give what they can. Yes, it's a way to connect. What's the problem?
As for the mental energy and angst that comes with now owning the gift, how often do you see your dad? Is he going to make you accountable for keeping it on your person at all times? If you don't want to just hold onto it, just give it away, and if he's on a fishing trip with you and you don't have it, tell him you forgot it, or you left it on some other guy's boat.
I know you're a hard-core minimalist and these issues upset your value system, but try to look beyond it. If simple living is about valuing relationships, take the gift and accept it as a token of love from your father and say thank you.