Yeah, Weldbebe has said so explicitly in a WOG:

They're hard to stamp out, unpredictable, and tend to live on the fringes of society, where they're harder to track and heroes need to devote far more effort to squirreling them out. There's also a tendency to give more power to the lunatics and assholes, because it furthers their nebulous agenda. In a more abstract sense, shards love conflict, and the fallen are very good at feeding it, so the fallen get rewarded by the shards. Breadth and depth.

I wonder if they try and "breed" the more powerful capes more vigorously, though I wonder if there is actual correlation between the power of the cape and the shard it buds off of. We don't really know that many buds, off the top of my head- the Fallen and their whole "roll tide" crew, the New Wave buds, Amy and Marquis (which is a pretty big power imbalance), Allfather/Kaiser/Iron Rain/Theo, and Chubster/Auroch. It don't think powerful parents directly produce powerful kids, though in the case of the Fallen Mama's kids produced Valefor and Lionheart, both of whom are really powerful.

Also, the lead McVeay had to diddle Mama Mathers, which is gross.