This link on Superheroes relative strengths has got me wondering again why Marvel and DC don't publish their extremely enjoyable "Who's Who" and "Marvel Universe" series anymore.
I know DC does its on-again off-again "Secret Files and Origins" series, but in my opinion, they give relatively little helpful data on exact powers and abilities. Even worse, the origin stories are remarkably murky.
After thinking about it a while, I came up with a few reasons why they might not publish these books anymore:

• They simply aren't profitable (Which with the direct market, I imagine this wouldn't be true)
• By not quantifying their characters, companies give writers maximum freedom.
• Characters are so convoluted in both universes it would be too hard to pin down an accurate description of them.