"Someone can correct me if I am wrong, but I was under impression that both DC and Marvel make more money from licensing their intellectual properties than they do from the comics themselves. If that's true, I doubt anyone in their corporate structure actually cares about the contents of the actual comic books."
It's evident this is very much the case, and part of the reason so many failed characters receive rebooted series on a regular basis is the desire to keep the rights to that character's brand alive for movie use. And yes, I suspect almost nobody at Marvel or DC today really cares about the book contents, as people like Diversity & Comics keep ably demonstrating.
Mind you, this is staggeringly shortsighted. The theaters are currently full of people watching the big Marvel movies because those characters are beloved; many have inter-generational appeal. But kill off that nostalgic attachment with magnificently stupid, insensitive, preachy, plodding, phone-it-in hackery and hideous, malformed art, and you will not be making the same movies about the same characters twenty years from now. There will be no audience for it. And both Marvel and DC have shown astonishing ineptitude at developing and building up new characters with mass appeal. (Hint: given the demographics of the comic-reading public, super-successful new characters are not likely going to be Muslims, angry black women, lesbian dullards or members of the PC freakshow. These may have niche appeal, but zero chance of breaking out.)