I agree that the elemental affinity is annoying and needs to have a rework, but I can see why they put the restrictions in place If you had Gear 2.0 without restrictions, you could find a set you like the look of, set the mods for your "God Build" and just infuse other armor to level it up as you need. While that seems like it's be ideal, it'd also be simple and wouldn't keep you considering your build and tweaking/changing it to fit the current fight. Much like we used to do - get your armor, fit a mod and forget it. Gear 2.0 is supposed to keep us as focused on building strong armor sets as we are on god-roll weapons. The elemental affinity is there to make sure we can't just swap out mods and be done - we have to grind for 3 different bits of armor for each element OR have a mixed up build with different elements on different pieces.