Yes they can! I had to give up my data plan several months back and have fallen from 30 or so to 50 or so, and have maintained a pretty good map editing rate. I think it goes to show that driving really can keep you in the running. I think that there are other new(er) users who have made significant jumps in the ranks.
I made from #115,000 to #520 in about 2 months so yeah - you can progress. The really high ranks are obviously far ahead of me though and I have no intention of trying to catch them.
If you are in an area where there are lots of unmapped roads or the map is a sea of unedited red lines then there is loads of potential. Obviously, the more developed the map becomes, points will become more dependant on driving.