DD Season 1 question: do you think that Elena Cardenas' murder could have been prevented? With everything Matt knew about Fisk, I think he should have persuaded Elena to take Fisk's offer, given he knows how ruthless and violent Fisk is in dealing with innocent people who get in his way. Karen and Foggy should understand this as well, to a lesser extent.
Technically yes, but that would have undermined the power of her role within the narrative. Elena is a heroic character because of the fact that she refuses to back down from the powerful forces trying to take over her home, and she symbolically represents the spirit of the neighborhood itself, and the people who Matt is speaking for as Daredevil. Seeing her fight back is different than seeing Matt– or even Karen and Foggy– fight back, since she’s not a main character and isn’t a superhero.
If she’d just given up, we would have lost a lot of what made her character powerful and interesting.
Elena’s murder is also a bit of a wake-up call for our heroes. At this point they know that Fisk is underhanded and dangerous, but they are still underestimating how far he’s willing to go to get what he wants. And Matt, who is most conscious of the threat, does think Elena should take the offer. He argues about it with Foggy and Karen. But at this point, none of them think that he’d have her killed– particularly since he’s just made himself a public figure. Her death is a turning point in the show, since it reveals to them all exactly what they’re dealing with. Yes, it’s really sad, and it’s easy to say that they all should have known better… but from a storytelling perspective, her death– and Matt, Foggy, and Karen’s failure to prevent it– makes sense.