Gonna play a bit of Devil's advocate here, but from what I've seen, a "translation" is basically "Hey, can you tell me what they just said?", and then you do just that, and better translations do a better job of relating it (using their own skill as a storyteller). But you play with fire as you go farther down that road, like Squaresoft's Ted Woolsey was a great translator, but everyone remembers that "spoony bard" line. Working Designs was great translators, but they just had to drop in a Bill Clinton joke.
Somewhere along the line, these sorts of "translation errors" got explained away with "Oh, but that's not a translation error, because this is not a translation, this is a localization. A translation tells you exactly what they just said, but a localization is an entirely new product, made by me, based on that thing that you mistakenly thought I was translating. And since I am the author now, that means that I have made no errors. I have free reign to insert as many of those lines as I want." Which invariably leads the fan/customer to say "Well fuck you then, and fuck your brand of localization." And no amount of internet videos defining/explaining the terminology will convince the fan/customer that they didn't just see what they know they just saw (even if they don't have the words for it).
Everybody has their own triggers, whether that's Robotech chopping up three different anime to make one larger story, or Sailor Moon's repeated erasure of LGBT characters (they erased Kunzite and Zoisite years before they erased Haruka and Michiru), or some Gamergator feeling threatened by being personally called out by the translator in the middle of watching an anime. And it always pushes them into this same conversation. It pushes them to say that you're just like 4Kids, because 4Kids was a notorious offender, and you can't say "Oh, that was different" just because they're a more extreme example of the same thing that you're doing.
At the end of the video, there was a quote from a translator saying that a translator is equally as important as the original author, and I know quite well that a good or bad translation can make or break a translated story (I've seen some great stuff that was just brutalized by an inadequate translation, and some crap that was significantly elevated and made enjoyable by a great translation), but, isn't that kind of... a really arrogant thing to say? IMO, the translator should usually (with some exceptions) try to work in service to the original story, and should give as much credit as possible to the original author, even if that's just lip service. That's just the respectful thing to do.
And when a particular line doesn't go over too well (one in 10,000,000, and it's the only one that gets noticed), if you don't want to argue all day about why you made that creative choice (because that can be Sisyphean), try to dismiss the conversation with "Sorry, my bad. These things happen when you're writing scripts all day long. Not every line is going to be a winner" instead of explaining how "localization" means that there are no translation errors, and then maybe people won't call you 4Kids. Obviously this approach won't work for everyone, but I think it's the best.