I get it. Perhaps this picnic group was playing their music a bit loud. If it really were bothersome, (1) move farther (and further) away to fish or (2) approach the folks in a friendly way and ask them if they could turn their music down a bit while you are fishing.
We are all just people. Let's treat each other with respect, the Golden Rule.
And I realize that there are two sides to every story and perhaps I am jumping to conclusions. If I am, I apologize.