So as I can see, you want SM disabled in Arena, but you're fine with having other 284 LK25hc weapons. Which means that most of your SM complaints are related to its proc /be captain obvious.
Well, alright, it's unfair. A Shadowmourne is a 284 LK25hc weapon and a trinket merged together. So basically, people complaints are about Warriors, Paladins, and DKs having a virtual 3rd trinket slot that no other class can have. Isn't that somehow comparable to Human's racial that lets them equip 2 DPS trinkets? Sure, most classes can be played as Human, but not everyone will reroll Human because of that racial, just like not everyone will reroll Warrior, Paladin or DK because of Shadowmourne.
So seriously, I don't care what you think of what I'm saying right now, but you complaining about Shadowmourne's proc is just like complaining about Human's racial to me (except for the case of a Human Warrior, Paladin or DK, these have 3 DPS trinkets
)