There's grind, and then there's grind. The trick with good grind is disguising it. Objectives, varied gameplay, byte sized things that show progress, etc.
A grind that requires you to run 15 dungeons, do 5 FATES, and craft 4 things would not be especially short, but it has you doing lots of different things and takes you around to various places. That will turn people off far more slowly than "kill 500 boars to get the thingies", even if the actual effort is basically the same.