Learning the script for Arabic, Greek, Russian, etc. seems too expensive an investment if one wants to learn just a little of the language (say A1 in the CEFRL). Likewise grammar beyond the very basics mostly pays off for the medium-to-long run.
Personal experience: I am studying Japanese, and when I finished a book that had 600 kanji, I felt that I pretty much had to choose between leaving it at this or going all in and learning 2000+ kanji.
Does it make sense for people who have different target levels to learn the same language differently? (If so, one needs to decide upfront how much one intends to learn.)