Future problem with thornmail

As of right now, seems to primarily benifit champions who stack armor, or scale with armor ( )

Rammus and Malph however are the ones that benifit the most from them. Malph has scaling damage and so does Rammus. Rammus however, has a Thormail for an ability, and a taunt to force enemies to attack him. As it stands, Thormail is an offensive like item (more so for Rammus), and the point where they spike somewhat. Thormail however, is not an offensive item for other champs, nor does it provide the same benifits to other champions without a taunt (Shen doesn't do well with this item anymore since W dodges autos intead of a shield, and Galio scales better with AP/MR). If were buffed, to the point of being must have or at least more gold efficient than it is now it would make tanks, not only harder to kill, but to be avoided at all cost. This would cause unnecessary nerfs to champs to balance their kit based off a popular item, which everyone can remember to never work out since the item always gets nerfed along with the champs. Thorrn buffs would also make Malph pick or ban and Rammus permaban. These two are also slated for a VGU in the future, which might also mean that their synergy with Thornmail might be taken away