Resistance and Defense in Unique IOs

Why are resistance bonuses from unique IOs affected by AT modifiers while defense bonuses are unhindered? Specifically, Aegis and Shield Wall uniques only grant 3% resistance to ATs with a 1.0 AT modifier, while most ATs are receiving significantly less. Gladiators Armor and Steadfast Protection grant a full 3% defense to all ATs.

I'd really like to know why the developers are so afraid to grant any meaningful resistance bonuses through the IO system. My ELA brute gets 2.2% resistance to all from Shield Wall-- the equivalent of 1.1% defense to all. What's so scary about meaningful resistance bonuses from IOs?

(PS- don't let me begin to rant about the other resistance/defense IO disparities...)

Well I could care less for aegis' psi res scaling, but the shield wall? That really does suck, they probably should fix it, and buff it to 5% while they're at it. (3% is pretty pathetic, especially since it is the only +resist unique when +def has 2)

I wonder the same as well. They're probably overly concerned with people rolling tank mages or prefer the peaky 'randomness' of defense versus the steady mitigation of resistance.

The Res bonuses out there are just so stingy, you certainly wouldn't build towards them. Or, the only decently sized ones seem to be for Psi and Toxic (mostly through purples).