Zygor is quite bad in <lvl20 areas, yes.
But later on if Zygor wants you to do only a few quests in an area and then go to another it is mostly because you need those quests because of a longer quest chain or prerequirements for other quests etc espcially on later areas.
All in all: Use it as a guidance, then maybe do some more quests around that area and go on