Can't Magic Resist Be a little bit better?

When you play as a tank against a mage top your an at extreme disadvantage without even knowing. Sure your goal is just rush these mr items and ill be all right but you still take a lot of damage... why? and the magic pen mastery in cunning tree. I guess riot is thinking that if a tank could take large amounts of magic damage that it would severely hurt mages impact but I don't think so at all (and mages is a favored class of mine, the class I mained when I started lol and the class I am prime in). Not to mention as a defensive champ, when you stack mr you are severely weakened against minion agro, monsters, turret shots, everones basic attacks and the mighty ADC in botlane which most often wont be there only adc.

So what's the solution? I know.... build hybrid defenses like these! right? WRONG. Building these so called hybrid defense won't protect you from the onslaught of mages alone.

There should be a secondary benefit to building mr. The Armor has the benefit of reducing dmg all non champ things can do to you while still reducing everyones basic attacks and AD spells. It's already bad that everyones mr scales slower than armor (Not that I want that to change, I find it very fair to mages and thematic because magic is a funny thing to learn to counter).

I appreciate the buffs got.. but I don't think it is enough sadly. We def champs need a small bit of easy access to mr if not make it better on a whole. Maybe a mastery that reduces spell dmg.. who knows?