I also write in Scrivener and love it -  mostly.
I think word counts are only important in this way: you have to keep moving forward, you have to move the narrative on. In order to know if you are doing this, you have to measure something and words is what you measure. The worst thing I find is to notice that the book has just sort of stopped. Then there is a problem. If it stops it means it's not moving forward. If it's not moving forward it might mean that I've lost the plot, or lost interest, or that it's ended, of course.
So I set a mor or less random book total and just write in that direction, trying to keep it moving, even when I'm deep back in what I've already written. 