Well yes, but considering every mon in the game bar Eelectross has weaknesses, I can't really hold "Super Effective STAB moves with 120 BP kill it" as a fault against Machamp. I'm not switching Machamp into Crobat. Crobat would switch into Machamp, praying that it doesn't get slammed by Stone Edge. Mega Kangaskhan gets killed by Terrakion and boosted attacks; but that stops absolutely no one from running it in... well, every meta it's allowed in, really.
On the upside, AV Champ is good at tanking reasonable attacks that one should be using machamp for, such as Raikou's Thunderbolt, Lapras' Freeze-Dry, Magnezone's Thunderbolt, and even takes strong, SE STAB moves like...
252 SpA Life Orb Alakazam Psychic vs. 252 HP / 4 SpD Assault Vest Machamp: 156-187 (79.1 - 94.9%) -- guaranteed 2HKO
And then murders with Knock Off.
Machamp doesn't always run Bullet Punch, considering it's literally useless against anything that has more than 20 HP left and isn't a Dugtrio. It also has a long list of moves it can use in that slot. One should always assume it has Bullet Punch if you're at 1 HP, yes, but it's not absolute. Dnite, will always win regardless of what Zammy is running (unless you have a Sub up and it switches in at like, half HP?) but with Sash you're assured that you can HP Ice / Dazzling Gleam / Thunder Wave / etc it. Without Sash you're not doing jack shit. With Sash, you can, if need be, get a hit on it or T-Wave it and kill it or halt its sweep. Azumarill, same deal: You can Energy Ball it even if there's a CB or +6 Aqua Jet incoming. Which, at 75% HP (Belly Drum -> Sitrus Berry), Azumarill gets OHKO'd if you have even the slightest chip damage, as opposed to Zammy simply dying and doing literally nothing. Donphan, same deal: Slam with Energy Ball, eat EQ / Knock Off, switch to Gengar or something and not care about the Ice Shard. Against every mentioned Priority mon, Alakazam loses NOTHING by running Sash, and against mons without Priority, it gains a large advantage against things like Aerodactyl, Kingdra, ChloroSaur, Kabutops, +1 Gyara/Gatr, etc that are all very important to stop. Alakazam has been killed by priority since what, Gen 2? Nothing is perfect, everything has faults. The set isn't made to counter Azumarill, it's made to emergency check setup sweepers and things like CB Nite.
I could also run Specs Zammy. Machamp / 90% of Dnite / Azumarill / Donphan all hate Trick Specs.
Oh and as a general announcement, I have free 31/31/31/x/31/31 Adamant Sucker Punch Golem clones that I RNG'd myself, if anyone planned on running one. Just VM/PM.