Thornmail Idea

What if Thornmail ALSO applied Grievous Wounds to the target for 0.5 seconds or so so that you can't buy lifesteal to make Thornmail a useless slot? In my eyes, while stats and crowd control effects should have counters, effects that MAKE an item should not be able to be countered by stats UNLESS it is entirely crowd control or maybe speed boosts since slows exist. So, I think Thornmail should reduce healing on champions that attack you to not only make lifesteal not counter Thornmail entirely, but ALSO make there be more variety in ADCs since this could possibly bring an item counter to Vayne and Kog'Maw since this indirectly powers them down slightly since they rely on %health lifesteal. Yes or no on this?