@Milanin you're confusing translation errors with spelling errors. they're not the same.
for example, translating 魔女 (majo) as "Demon Woman" is a translation error (it's witch), but translating Majo as "With" or "Widch" is a spelling error, not a TL error. it's translated properly, it's just spelled wrong. if written in a sentence, the vast majority of the time you'll figure out what word they meant almost instantly due to context. with translation errors, however, it's the difference between a demoness with goat hooves and horns, and a girl on a broomstick. suddenly "The Witch's House" becomes Helltaker.
a paper filled with spelling and grammar errors will be readable, if mildly annoying, as we're good at fixing such errors automatically in our heads (which is why proof reading is so important, since writers will mentally auto-correct their errors and thus never notice them. even the first proof reader will typically miss some of them, so you generally need 2-3). but a perfectly spelled paper filled with translation errors will be nigh-unreadable and indecipherable. MTL is a perfect example. I'd much rather have a single person butcher english but translate it properly than have a machine spell mistranslations correctly.