I shoot a 26 Nosler with a brake and have carried it around the world on many Ovis and Capra hunts.
On those hunts, I always have time to put in hearing protection prior to shooting.
I did forget once shooting a Coues deer on a desert bighorn hunt and my ears were bad after. I try and use hearing protection and always carry some for the guides and insist they use (they don't always listen).
I do like the brake though. it makes the gun kick like a really loud blasting .22 LR. It is quite accurate and follow up shots if needed are nice.
This said, in a DG situation you may not want to have hearing protection in or may forget due to stress and I can see the thinking (which a few guys mentioned) behind not having a brake in these situations being sound logic.
That said...... I think a .375 Ruger with a brake and a 20" barrel would be an amazing Moose/Bear/DG/PG rifle that would carry well in a scabbard, in a boat, in the willows or across Africa in thick stuff.
Someone who doesnt like recoil could shoot further out (in a moose/bear/PG situation) accurately without recoil prone or off sticks.
I would personally consider trying it without the brake and seeing if the recoil was manageable. I think as long as you had a conversation with your outfitter, and the guide was ok to get his hearing protection in you are being respectful.
I do not like rifles that recoil and sold my .500NE after shooting it one time.
I am ok with being a