It's not where it comes from, it's the process. The reason american attempts at 日本动漫 fail so hard is that the animators are not willing to put in the kind of time, money, & teamwork it would take, Also, American 动画片 is 90% condescending, if for no other reason than fear of getting sued. That's no good for a medium generally aimed at older audiences in a country where 动画片 is still seen as a children's thing.
The blatant amerime look has too much lazy western influence in the 设计 where it looks like they're trying to poorly imitate the 日本动漫 style of the 90s. It's similar to the Uncanny Valley effect 你 get when watching rotoscope animation; something seems off & it's unsettling.
I find that when cartoonists are desperate to recreate a concept they can't grasp 由 throwing as many cliches into it as possible, the results are insulting, having only stereotypes to work from & no experience working with people who know the industry.
It's like growing up with rock 吉他 lessons, then buying a synth 钢琴 on a whim & trying to 撰写 a techno song. If 你 want to make a real anime, 移动 to 日本 或者 South Korea & get a job as an animator there, because their 动画片 industry doesn't work like anyone else's.
