Personally I don't mind the use of peppered Japanese if it makes sense in some way (Eg: It's a character whose native tongue is Japanese) or the author wants to use a word with no proper English translation. I've also got huge respect for authors who do their research and know what they're talking about when they use fragments of a language as difficult to master as Japanese. But even in these cases it has to actually make sense to work. It drives me crazy when I see what I consider lazy translators. Those are the folks who just slop a bunch of English into babelfish, hit a button to make it Japanese, and just copy and paste that into their story. Half of the time it's a mess because those popular translators spew out the closest equivalence. My ultimate pet peeve is getting trapped in the middle of a chapter where it's nothing but "kawaii desu!". It makes me feel like I'm being told the story by a weaboo.