Part of that is that the original company spent a lot of money on the production, so they usually don't skimp on the voice acting / audio. If you're spending $350,000 on production per episode then you're not going to skimp on the audio by hiring the sound editors's niece as a voice actor and using a Casio keyboard for incidental music. You already spent so much money, so making it sound good is good business sense. Skimping on the audio for these guys would be like putting their expensive product in cheap shitty packaging.
Whereas you can contrast this with the economics for dubbing companies. (1) they get the show pretty cheap, since the export market is an afterthought for shows that did well in Japan, or a dumping ground for shows that did poorly. (2) imported shows only have a niche audience (3) half your niche audience only wants the subs and would buy them whether or not you dubbed them at all, and half the people who prefer dubs would go "fuck it" and watch it with subs anyway if there were no dubs if they really wanted to see it. Let's face it: the audience for a
niche product of this kind who are also noobs who only want it dubbed is a
very small slice of an already-small pie. People chasing up such a niche product are usually all-in in the first place. The economics of this mean that dubbing is an added expense on a cheap product with low profit margins that many people would still buy even if you never bothered to dub it at all. That means skimping on the audio is good business sense.
Yeah, so good economic reasons there why a very low amount of effort is spent on dubbing most series. If you watch subs, then the overall quality of the voice acting is a lot more consistent, since in Japan voice acting is a make-or-break career with a much larger talent pool. The American dubbing companies by comparison tend to have a small pool of voice actors specific to that company who are low-paid contract labor. And that's not getting into game dubbing. There was one small company that imported a game, and the lead programmer got his family members including his mother to be the voice actors. The result was an obvious shit-show that ruined the product complete.
EDIT for lulz
https://kotaku.com/not-so-good-voice-acting-explained-5014864?IR=TYeah, this is pretty bad but I've heard bits and pieces of anime dubbing that's almost this bad too, especially for lesser-known series.