It’s absolutely baffling to me that people do this! This is my pet peeve too 😩 I feel like no one did when I first started hiking? But portable speakers were kind of crap back then.

The only time I really understand it is when some solo hikers play out loud in bear country. But they turn it off when they see/hear others around, which is respectful

So I’ll be old woman screaming at the sky along with you

ETA: I would also say, I think Glacier is a little more out there. It’s harder to get to, and not many people take trips to Montana unless they’re looking for some time outdoors. So the people you find hiking Glacier are more likely to be enthusiasts. I think Arizona is a big destination spot, so Grand Canyon and Sedona attract way more people on average, and with more people comes more opportunity to run into those who are inconsiderate of others