I've noticed that there are less opportunities for magic resist and it was already a small issue in season two, but now that Force of Nature has been taken away and the magic resist on every item has been reduced , I'm worried that a fed mage might run the game or that Galio, (for lack of any other champion that depends on it) might suffer. If this isn't seen as an issue from anyone else then I'll keep quiet on this subject henceforth.

TL;DR
Magic resist items are too weak.

I agree

Bulwark+GA+MErc's = 200 Armor +180 MR on most tanky built champs

WTF are you people smoking? On top of that there are 4 ~50MR options which tanks can use building out of negatron.

Oh and bulwark is a 30MR aura.

Only if by less opportunities for magic resistance you mean 19 items that offer magic resistance, with at least 3 final items tailored to survival, physical damage, magical damage, and even supporting allies.

Taking Force of Nature away without adding anything to take its place completely screwed some people over.

If you're a support against a team with some heavy AP users, buy a Bulwark .