Using Google Translate isn't any better but it's actually a lot more understandable at times when people decipher it lol -- You get the idea across but it won't really save you. A lot of Japanese know basic english, this is true -- however most prefer not to use even that because of either comfort level or because in Japan it's not a national language, therefore you rarely need to even use your requirement of it.

What Levian said is also the other reason Japanese tend to stray from the AT -- Using basic words with it doesn't translate to what you're saying at all -- If I see <May> <Bee> while on the Japanese settings, I'm not going to assume you're saying "Maybe" or even anywhere close to it -- I'm going to be confused as hell first then not caring second. Japanese players understand basic things like "Ok" and abbrivations like 'brb' 'afk' '(class/jobs)' etc, but most want to communicate beyond basic things, especially in content.