Yup, I agree with this. Marketing, I mean, it's one of the biggest reasons. Here's a great example: the last Pokemon movie had a pretty cool soundtrack, and this was released as an OST as normal. But when translated outside of Japan, they... changed about half of the soundtrack, including all major tunes. I don't know why, but it was good too, about on par with the Japanese. This version didn't get an OST release AT ALL, and there's no clean versions of those tunes available anywhere.
Unions are the other half of things. Specifically, animators are the ones paid far less in Japan. In the west, and because of that, it's why anime is so ridiculously loaded with animation compared to actual writing. In Japan, it's not uncommon for anime to have 100+ staff members on a single series... but it's highly uncommon to have more than exactly two writers: one to write a manga or light novel, and one to adapt it to animation. This is in contrast to Western cartoons, which normally have writers numbering in the dozens. So much so that it's extremely noticeable that NuPPG only has two.
(Western movies, on that part, are in a similar situation to anime here - have a small amount of writers, a massive amount of animators / set designers / makeup artists, and make millions from merch and advertising. For perspective, Iron Man had 8 writers total, and 7 if you don't count Stan Lee).