I'm not part of the industry but my impression has been that their business model and practices came about in a time when they had an effective oligopoly. There was Marvel, there was DC, and there were a handful of also-rans amounting to a small fraction of the industry (and those competed in other niches than superheroes, like Archie). They designed how they sell around this situation and when actual competition showed up I don't think the comics industry handled it very well. Manga not only cut into the monopoly but have successfully entered niches that the big two pretty much ignored, such as romance and slice of life.
It doesn't help that manga are cheap to produce. Minimal use of color, cheaper paper, and generally produced in a "throw everything at the wall" strategy make them inexpensive. Then add in that successful manga have effectively already paid for themselves in the domestic market so the US market is pure gravy and it's not hard to see how they're undercutting the majors pretty heavy.
Quite honestly the reactions of the Comics industry haven't been terrible for what they had to work with. Switching to a movie primary strategy with the comic books themselves essentially becoming advertising vehicles for their movies and TV shows seems to have been quite profitable. Trying to position themselves in the market socially much less so of course.
