Why do Harley Quinn and Poison Ivy still qualify for a series?

The new miniseries starring Wally West allegedly searching for redemption isn't the only one of its sort spinning out of the abominable Heroes in Crisis. The Hollywood Reporter says there's even one starring 2 notable villainesses:

As its title suggests, Harley Quinn and Poison Ivy is a six-issue series focusing on the two characters as they come to terms with the events of Heroes in Crisis. That’s no small thing, considering those events included Ivy’s death and subsequent rebirth as a plant-based lifeform, as well as Harley being accused of mass murder and going on the run as a result. The series, by Jody Houser and Adriana Melo, launches Sept. 4.

And I guess Ivy's now in a role similar to the one Dr. Jason Woodrue took up when he devoured a chemical in a Green Lantern backup story in the Flash in early 1976, becoming the Floronic Man. What I'm wondering here is why more criminals are deserving of even so much as a miniseries, which dampens the impact of more important heroes. Much like the upcoming Flash Forward miniseries, this too is decidedly another reason to avoid DC output so long as Dan DiDio remains at the helm, and this sounds even more revolting than the former, maybe because they expect us to sympathize with criminals?!? Which has been exactly the problem with quite a few superhero comics over the past 2 decades, now that I think of it, as more emphasis was put at times on villains than heroes. No wonder story quality's plummeted so badly.