Black Cleaver I don't have a problem with, that is meant for bruisers, and it's an item that assassins had to pilfer into their builds.
However, I do have an issue with the likes of Pantheon and Wukong much for the reason people hate Talon (or AP assassins like LeBlanc and Katarina); when they build these items, they can get on your face and kill you with next to know counterplay. My issue is with Pantheon more than Wukong in that situation. At least Wukong needs to use his ultimate to kill you. Pantheon? He just needs to use his W, which is downright coded as an undodgeable auto-hit stun whose outcome is determined when the skill is activated, then use his E and Q to nuke you down.
.....Pantheon has made me very salty over the recent months, not gonna lie. With him specifically I'd like to see him either get nerfs that deal with his incredibly reliable 100-0 combo, or pushed up on the rework list.
(ahem) That aside, I don't like it on them in general because they both have free means of being very bulky while still 100-0 like an assassin. Bruisers are supposed to be a middle ground between assassins and tanks, dealing consistent damage while being tanky, but requiring that tankiness to deal their sustained damage.