For very good reasons: None of these characters have the Echo. The WoL being able to take down Primals, whether alone or in a small group, is the reason for them being known as a hero and special. While you were becoming a well known adventurer amongst the newbie ones at the start of ARR it was your fight with Ifrit that catapulted you to stardom, and from there you were given more oppurtunities to fight stronger opponents because you proved yourself again and again. These other NPCs have proven themselves against various other monsters and other people, BUT none of them have the Echo and thus are very much in danger of becoming tempered.
Also if you did 4.1 some of our non-Echo NPC allies did in fact help us fight Lakshmi. And you know what happens if you let one of them get hit by her orbs? Immediatelly becomes a Dreamer, do not pass Go do not collect your retirement check. Also if the story actually continued from there we lost atleast one of our better allies, or possibly all of them if it snowballs from there. The story gives good reason for why many NPCs who are as powerful or near enough to our level still can't do everything we can.
Also something something "we did all the hard work, why does so and so character get all the credit?"
