Wow, I mean, god damn, you just had to bust out all of the hyperbole in a single paragraph, damn. And you wonder why Riot doesn't take you Fiora haters seriously.
Here, since you're just gonna keep babbling and throwing hyperbole at me, I gotta work with hard math:
Fioras %HP damage per vital is 3% + 4.5% per 100 bonus AD at lvl 18.
Let's look at your proposed build: Titanic Hydra gives us 50 AD. Black cleaver gives us 55, for a total of 105 bonus AD. For a total of 7.725% HP true damage per Vital (We can work out more AD into the build, but that build is already squishy as it is, since it has very little armor, if we add a couple AD items, we're not even talking about bruiser fiora anymore, squishy Fiora has very simple counterplay focus and delete her quickly).
Let's assume this Fiora is SUPER SKILLED and managed to pop a vital on our tank before even turning on the ult. Let's also assume this tank was either terribly positioned or kinda clueless and couldn't hide one of his vitals on terrain, this super excessive scenario means that Fiora manages to land 5 vitals on him, for a total of: 38,625% HP.
Now 40% HP is a lot, but it's FAR from INSTADELETE like you're all claiming all the time. Not only that, but there's not really a lot of AD in that build, and pretty much 0 armor penetration, so she's not going to be dealing a lot of non-true damage to a tank. And moreover there's no lifesteal in that build (Lifesteal items make you squishy and easy to burst, see paragraph 3) so she can't sit in front of the tank fighting.
Now that we've stablished bruiser Fiora is no threat to tanks, it makes sense that a high-CC champion that has nothing to fear from her could lock her down easily, not allowing her to go for the squishies she wants to burst, and since she's locked down, let the carry melt them through DPS (like we would with ANY OTHER BRUISER
).
If as a tank player you're losing games against bruiser Fiora, then you're probably not peeling for your carries, or mispositioning terribly in teamfights.