Think about this: you might go 5-10 Km to buy bitcoin. But would you go 20? 50? If they saturate they can make it easy for everyone. Just a guess. :-)
If there would a Bitcoin ATM 50 km away from the city where I live, no doubt I would use it. Spending few bucks on gasoline and 1 hour of time is not so big problem IMHO.
I also would easily spend an hour to go to Bitcoin ATM if I had one 50km close to my home!