David Welsh has an excellent writeup on the issues faced by manga targeted at men. It’s quite eye-opening to someone used to the male domination of the American comics industry. In this case, the tables are turned, and the books aimed at adult males don’t seem to have the audience (and thus sales) to continue.
He quotes someone named Kethylia:
“… if it’s not clear to you by now who IS the demographic with the buying power, I’ll spell it out for you–Girls and Women. Who do not, surprise surprise, flock to Blood and Breasts in satisfyingly large numbers.”
Seinen (men’s) manga doesn’t have the crossover appeal needed to succeed in the US. Although boys will read shojo (girls’) titles here, not a lot of women seem to be interested in moving the opposite way. (I’m in that group myself. Shojo may be fluffy at times, but the horror manga I hear recommended sounds too strong for me to enjoy.)
And not to muddy the issue, but I’m never surprised to hear of any problems involving Dark Horse publications. In this case, they’re not a dedicated manga publisher, so they don’t have the loyalty or audience awareness of some of their competitors, yet they seem to be interested in establishing manga as a solid product line.
To see them concentrating on the male audience almost exclusively fits in with my impression of the rest of their publications. With the notable exception of Little Lulu, most of their releases seem to me to be firmly aimed at the traditional young adult male comic shop audience. Which is not enough to succeed.