They just nerfed top lane smite for the offensive capabilities they were using it for. Red smite was nerfed to 4 seconds and cinderhulk only does half the damage it was doing before. IF top laners still want Smite for the %HP, they will. But they are sacrificing even more now, which is appropriate for how good %HP is for tanks. I don't think we'll see much of it anymore because of the offensive capabilities taken out of Red Smite Cinderhulk.
You still don't get the main point I was trying to make. LANING TOP LANE TANKS HAVE A S*** TON OF INCOME. They don't need an item that gives more HP than Cinderhulk. They already reach 4k health on a regular game
together with runes and masteries give over 2000 bonus health. And that is just 3 items.
Say a toplaner and a jungler reach lategame. Both are tanks, but the toplaner has 14k gold and the Jungler has 12k gold, which is not an unreasonable difference. With that gold they can buy most of the same items:
but they will differ in one item because the jungler will take
whereas the toplaner will take
or
/
(because Maokai). But wait, the toplaner has 2000 more gold. (2500 + 2450 + 2750 + 2800 + 1000[boots] = 11500 gold) on the Top Laners items before his last item, he would have at least one more part to an item at this point if not a completed one. Whereas the Jungler would be behind in that respect, not to mention that Junglers are the second most responsible for vision on the team, meaning they will have spent more money on Wards or a Sightstone during the game.
Let's say that we got rid of the %HP on Cinderhulk, we will just compare the difference between a laner and a jungler tank.
Top Lane:
(11550 gold) (1700 Health, 195 armor, 55 MR)
Jungler:
(give it 500 health flat)
(10300 gold) (1430 Health, 125 armor, 40 MR): now let's convert the health to the actual Cinderhulk numbers 1230 x 1.25 = 1538 health, still UNDER the flat health given to toplaners by buying similar items. Even if you don't get Sightstone and get another item, you will still be at around he same HP values as a toplane tank. I'll even get rid of FH and substitute Righteous Glory and then get Warden's mail (1550 x 1.25 = 1938 finally breaking the amount of health a toplaner would have but with less resistances meaning less effective health.
Now if you give %health to a toplaner without sacrifice, they will be able to take a greater advantage of it than a jungler could. Tanks are doing just fine as it is in the toplane, and I don't see any reason in giving them another strong item pickup. Particularly one as powerful as you are suggesting. Replace Warmogs with your item that gives 800 health and 30% bonus health in my toplaner example. We just need to multiply 1700 by 1.3 and get 2210 HP (without runes or masteries) and that is only 4 items. Tack on a Warmog's on top of that and you will reach 6k health easily on someone like Sion. Also note that if you make it a unique passive, Jungler's would not be able to use the item effectively, putting them farther behind the lane tanks. That's my piece. Hopefully, you see what I'm getting at. Later. Peace.