A very large number of people, and this includes campground managers, Take a router out of the box and plug it in.
Some may change the SSID, but change the channel? How do you do that?
Thus, all the routers are on the default channel of six.. and do indeed interfer with each other
Turn off your SSID and you can still connect to it (Your computer remembers) but the othes will not even see it in all likelyhood, I do a scan for routers and try to pick a non-interfering channel.
1, 6 and 11 are non-overlapping, other channels will overlap one of those and/or one or more of the remaining channels.. Assorted sources.. Channel 1 is also licensed for another more powerful service.. Just so you know.
NOTE: I said others won't see it in all likelyhood.. I can see no-ssid routers.. I can't connect, but I can see them.. Also do put a password/passphrase/key on it if you have not (As I recall Cradlepoints' come that way, the last six of the MAC address, change it if you have not)