Because A LOT, I do mean A LOT of attacks have S/L in the attack. That is checked for defense. Black Scorpion Shield is S/L/E Defense. So E is covered also. Ranged characters usually have higher odds of having a higher R defense, do to recipe sets for ranged attacks. I don't know if y'all are new, that's cool if you are. But you guys really should sit down & deep dive into Defenses and what mobs use for attacks. You will face a lot of S/L or attacks that may do E dmg, but also have S dmg in it(Thus defense). etc... A lot of CC has S/L/E tied to it. (Cept things like Carnies, which mostly pure Psi or Ranged, but some do have S/L)
Just do your research.