I'm currently reading 'The Legion Companion', a book I picked up because I knew next to nothing about the Legion of Super-Heroes but was aware they had a devoted fanbase, and wanted to find out why. It's been of sod-all use in that regard (it's a collection of interviews with various Legion writers and artists, designed to be read by people who are already intimately familiar with the LSH), but it does give me an idea of why comics today are failing.
Reading these interviews, you'll find old writers, editors, and artists talking about comics at newsstands (when was the last time you saw a comic sold outside of a comic shop? OK, yes, maybe a bookstore, but they don't sell them in drugstores, at supermarkets, or anywhere the direct market can't reach.) They talk about letters columns (vanished as well.) They talk about how they wrote self-contained stories for the casual reader (multi-part stories used to be taboo at DC, now they're mandatory everywhere.) They talk about doing eye-catching covers (sure, superdickery.com jokes about 50s DC covers, but as crazy as they were, they certainly made you want to buy the issues.) They talk about how they didn't expect anyone to be into comics for more than two years, so they had to keep doing things to get new readers interested (nowadays comics writers assume every reader is a long-time reader and is intimately familiar with the characters' backstories and key historical points.)
It's like a glimpse into an alien world.
Now, I'm not saying every single one of these changes was a bad thing--I'd be crazy to suggest that there's no room for multi-part stories, for example. But it does occur to me that comic books, as they were constituted for the first sixty or seventy years of their existence, were designed for the general public (if only the juvenile element of the general public), and that they had a goal of getting as many people as possible to look at a comic, see the cover, and at least consider purchasing it. For the last twenty or thirty years, they've marketed to an increasingly smaller, self-selected market, counting on brand loyalty to outweigh the fact that nobody knows their product exists anymore. And they wonder what's going wrong...
I'd have to say, if I were to be put in charge of Marvel/DC, the first thing I'd do is market a "Comics Treasury" monthly. It'd be a magazine, say 100 pages, and it'd have four or five self-contained comics featuring flagship characters on a rotating basis, it'd have letters and spaces for fan-art, articles on the company's history, continuity, and so forth that would be fun, interesting, and glorified ads for their other products...and most importantly, it would be marketed wherever anyone had a magazine rack. And the advertising department would make sure, every month, to have at least one page of ads for local comics stores, and those local stores could purchase ads at a discounted rate.
That'd be just the start--I'd also tamp down on excess continuity, rampant cross-overs, reboots, et cetera, and ramp up the newsstand programs and bring back the letter columns...but at the very least, I'd want a single product out there aimed at casual readers that would increase visibility of my entire line of products.
Something like that is necessary, I think. They have to start growing their business again. Because at this rate, comics will soon be down to the point where they're trying to sell every single copy to one very rich fan. And that's just not a viable business model.