That's a fair point, but there are ways around that. An option to disable. Partial physics, like I said, like they did for Diablo (not for mobs, world junk, etc., just chest pieces). They were talking about at least doing for Legion at the BlizzCon before it went into alpha, but, like you said, performance was a consideration and they were working on a lot of other new tech.
The guldan staff and horde axe have them with multiple points on their doodads, I think. Several belts also use physics-- post-mop: Strife-riddled Cinch, Demonbuckle Sash of Argus, Wild Combatant's Cord of Prowess, Phantasmal Cumberbund, Warmongering Combatant's Cord of Prowess, Primal Aspirant's Cord of Cruelty, Hexweave Belt, Rockfall Girdle, Ley-Touched Cord, Enhanced Worldscorcher Cinch (all 3 variants), Sash of Diabolic Preparation, Shadowfel Cord. Some shoulders post-mop: Fierce gladiator's silk amice, riven priesthood amice, ferocious combatant's silk amice, caretaker's budding mantle, vileweave amice, fel-infused spaulders, shoulderpads of chaotic thought, mana-flecked mantle, imbued silkweave epaulets, netherworld's march amice, hexweave mantle, moltonoma's magma mantle, lightbinder shoulderpads, mantle of swirling light, steamburst mantle, auchenai keeper mantle, windburnt pauldrons,corrupted mantle of the felseekers (4 variants). there's a couple staffs, too. (some of these are varients with different names, but I listed them all since making them way more accessible also means more people will wear them) This is just from cloth I'm able to wear. I'm sure there's tons more. I know there's some mail belts from wod and legion that do.have you ever seen the pandaria belts that have physics and why they stopped and now only have them on a few new weapons (the 3 flails in artifacts)