I really want to get involved in this discussion, but I'm afraid of catching spoilers. So if anything I'm saying has been stated, my bad. I haven't read every post.
1. S.H.E.I.L.D. may not be aware of Cage just yet. I think all of this happens before Jessica Jones. How much before, I don't know. So Coulson and Co. are still up to their necks dealing with Hydra.
They've not yet came looking for DD or Jessica Jones either. I'm betting on Coulson making an appearance on the Defenders at some point.
2. Some of the changes people want to make to Luke Cage, wouldn't be Luke Cage. You'd end up turning him into a whole different character. Luke Cage, at his core, is a street level guy. Always has been. So, this is his environment. The Hood. As much as I'm not into the character, it would be wrong to change him. He has a lot of fans both black and otherwise.
3. Ra, I don't see anything wrong with black people having perfect superheroes, too. Those are the heroes I've always liked the most. Something about a hero doing the right thing, having the perfect solution, and standing morally incorruptible in defiance of all odds, gets me every time. As unrealistic as it might be, I enjoy and embrace that part of the superhero mythology and I want to see black faces behind those masks making the impossible, possible.
It's for that reason characters like Wolverine, The Punisher, and etc ... don't appeal to me. Call me corny. But, whatever.
I'm not coming back to this read until I've watched the rest of the series. Just so ya'll know I'm not ducking anyone. Just don't want to see any spoilers.