Well, I think the real blame then is American Censorship.
Look at this. Kekkaishi is aimed for kids to tweens in Japan.
But think of Kekkaishi in American television. Would you really see Kekkaishi being aired in Disney Channel, Nickelodeon, or Cartoon Network?
If it somehow did, Kekkaishi would be heavily censored and cut. I think that was why it aired on Adult Swim. Adult Swim is the only way Kekkaishi can air on tv without being censored.
Shows like Bleach and Fullmetal Brotherhood are also aimed for tweens and up. And they are only aired on Adult Swim.
Heck, Fullmetal and Bleach would NEVER air on Disney Channel, Nickeolodeon, or Cartoon Network.
Digimon which is DEFINITELY for kids is CENSORED in Disney Channel. DIGIMON!!! If a show as light as Digimon gets censored, what chances does a show like Kekkaishi have on Disney Channel?
Ultimately, the only place Kekkaishi could have aired uncensored is Adult Swim.
Digimon rules!!!!