There are far greater issues. Even if his grammar wasn't terrible, he already applied previously to the clan, and was rejected. Granted, he was a 2nd dan, and is now a 4th dan, but I find it hard to believe that his apathy magically vanished over such a short amount of time. Personalities don't change like that.
I don't mind shitty grammar in the casual sense, but if you're going to apply to a clan, and essentially try to impress the clan, I would expect a little effort into being grammatically correct. You wouldn't go into a job interview looking like a bum, and you shouldn't submit a perfunctory application dolled up by a spinning .gif animation.
Especially being his second application, I expected more. If it was his first application, I would have probably accepted it, but the lack of motivation that I saw in the first app outweighed the ~decent app the second time through.