I think this is pretty accurate.
Also, thinking on it more, the biggest weakness of the thread's premise is the contention that comic-book culture was hidden away among geeks for decades until it was only recently discovered by the mainstream. It makes sense if you look at Hollywood movies, but that's a very narrow way of approaching it.
American comic books have been part of the pop culture mainstream for
years. Back in the 1940s, and for decades afterwards, icons like Superman and Batman were selling close to a million issues a
month, each. Superman was a big hit on TV in the 1950s, and Batman followed it in the 1970s. Spiderman was an early cartoon, and had (and still has!) his own nationally-syndicated newspaper strip. This seems like mainstream success to me.
Interestingly enough, in those early days anime was finding an audience of its own on Western TV, unbeknownst to its viewers. Shows like Speed Racer, Gigantor, and Kimba the White Lion were localized for US shores, and delighted children. Even my parents remembered the Gigantor theme song when it re-aired on Toonami briefly.
Even after all-ages anime stopped being disguised as something else, shows that aired on Saturday morning or on weekday afternoons earned enduring success, like Dragonball, Pokemon, and Sailor Moon. Similarly, cartoons of Batman, Spiderman, and X-Men kept those properties alive for kids even as the comic industry began imploding on itself.
The difference between what happened next, however, is in the money. Warner Brothers owned DC for ages, and comic contracts made lucrative characters the property of publishers, not creators. Even before the turn of the millennium, comic characters had seen multiple successes among broader popular culture, and they were in the hands of companies that could make big bets and reap the full rewards of their successes. The progression made business sense.
In the West, anime was in the hands of a scattered handful of companies that were trying to keep up with a boom. The large companies that held the rights to major properties generally weren't interested in making big bets on the West, and those that were got nailed hard when the market went bust in North America. The aftershocks of that are still being felt today. Daryl talks about how manga is growing year on year, but yearly revenue is still less than half of its peak of $200 million in 2007. The anime retail market is no healthier. There is still a lot of uncertainty because of the recent collapse, and no huge players who can throw lots of money at a mainstream push.
And going back to jiji's point, think of the licensing structure. Disney and Warner own the rights to the properties, own film studios, and are already well-integrated with merchandising. They're well-positioned to make tons of money off of every single aspect of a mainstream success. Anime, on the other hand, are largely produced these days in "production committees" consisting of multiple companies, each with their own interests. A broadcaster, an anime studio, a music label, and a manga publisher might all get together and pool their money to make a show, minimizing the risk to each if the property fails. These are ultimately conservative enterprises. The money would be fractured even further if they had to partner with a Western company to handle the distribution or creation of something focused on the Western mainstream.
A Western company could try to buy a license outright and go it alone, but there's no precedent for success, so I don't see why they'd try to probe for that uncertain vein when there are rich supplies of comic and YA properties ripe for the mining.
