From an interview with manwithoutfear.com:
“[Daredevil] had undergone his crisis of conscience. Theoretically, he'd become a better person for it...but I'm suspicious of easy conversions. Either way, he had to bring what he'd learned back into the world. I wanted to get him out of the narrow confines he'd fallen into (short-order cook in a small NYC neighborhood)--make him work with other people in a "new" environment (that he'd once enjoyed), in a situation (highly visible superhero--that he'd once enjoyed but now didn't)--and see how those challenges affected the very different man he'd become.
“But also, the Black Widow would have joined the WCA, and they'd have been based in the town where he and she had been happy. Bottom line, I was angling toward DD being with Natasha at work, and Matt being with Karen at home, and seeing what happened. Living in two very different worlds with two very different women...”
Unfortunately, during the fill-ins issues before Englehart would start he run, Ann Nocenti had brought Daredevil and the Black Widow back together in a different way that he wanted.
And from steveenglehart.com:
“Frank Miller had concluded his run on this book and I was supposed to take over after three fill-in issues. But in that interim, an editor [Ann Nocenti] took it for herself, so this is it for me. I did an all-black splash page to indicate DD's POV, and a few other fun things, but since all the plotlines I set up went to waste I put my "John Harkness" pseudonym on it.”