Exhibit A: The gap in actual damage reduction between defensive and offensive armor is negligible
Exhibit B: Interrupting enemies with your armor-augmented damage means that they won't attack you
Exhibit C: Monster AI is so inadequate that it can unambiguously be described as lobotomized, so you shouldn't be getting hit anyway
Exhibit D: Despite being offensive armor, the Spiral Demo set isn't worth the trouble because pre-T3 bombs are pathetic and in T3 Chaos does everything it (and every other armor line) does better
Long story short: Get Wolver (or Gunslinger if you like Alchemers) for your first set, you'll learn to dodge. Don't bother with anything else until you've been to the Core a few times and have resources to spend on armors like Chaos that only get good at 5*. Got something else at 2*? Vendor it. Already committed to an inferior line? Upgrade it since you're stuck with it, then start on Wolver.
*activates flame shield*
Effectivity vs fun.
Some people enjoy beating monsters wearing a jelly suit and a spur, even if having wolver with a brandish and autogun solves problems 5x faster.