BoRK and Wit's are only a real problem on Warwick (I love Warwick), even then it's only a problem because he can hit you 5 times in a single second with his ultimate. I used to play some Kayle with Old Devourer, Hurricane, Wit's and Nashors and found it to be decent, but not OP. I eventually dropped building Wit's for a better AP item, felt that was more useful. I also felt Jax wasn't broken with Old Devourer, BotRK and Wit's End until you hit like 40+ stacks on Devourer, then, all those on-hit effects+Jax innate scaling (you wouldn't hit a ton of stacks until late game) made him pretty strong.
But I agree with you, anyone saying "It's X item or Y ability" is creating a hell of a lot of collateral to ward off actually changing the item that started this: Sated Devourer. I don't want to see BotRK nerfed because it has got a use on bruisers or ADCs in a tank meta, and, as someone who loves Warwick, I remember what happened earlier in the season to my beloved wolfman upon the new jungle change. The change to the jungle, (WW could stay in it forever and no one else could) coupled with Red Smite applying true damage on hit (opposed true dmg. burn), made WW a pick or ban (meaning I never really got to play him), and when Riot saw "League of Warwick," they may have hit WW too hard, nerfing his R damage and W duration, if memory serves they also changed the way red smite proc'd; and slowly tuned the jungle down to the point where a few more champions could survive an initial clear made all the more challenging by both side laners also wanting to start a camp, thus removing a possible leash.
Anyways, my point is, Riot changed an item (plus the map itself), making a champion OP, and, instead of taking a look at why the champion was OP (item too stronk, one of few champions that could clear jungle + reduced jungle XP made it a fair trade off in terms of farm for guaranteed kill @ L6 vs occasional under-leveled gank) and responded by gutting one of my favorite champions instead of looking instead at the conditions surrounding his ascent. Sated Devourer makes me nervous that Riot hasn't learned a damned thing from their rollout of Feral Flare, to J4/Lee Sin only, to the power creep of Cinderhulk and the of annoying mid-lane applications of Runeglaive.