A more direct translation of 'those that practice more learn more' seems fine to me as well. I'm a native english speaker, and I wouldn't find anything unusual if someone said that phrase.
Agreed. Marked me wrong for the same thing. Really "Who" is "Quem" not "Que". Another flaw in duolingo.
I reported "that" instead of "who" being considered incorrect. Maybe they'll start to accept it.
Thanks. They accept it, now.