I keep hearing that hiking is getting less popular in North America.
Not so in Norway:
… the Norwegian Trekking Association has 222,291 members. Around 7000 of these joined this year, an increase of 3.6 percent compared to last year.
A trend?
Head of communications at DNT, Merete Habberstad speculates as to why membership keeps increasing:
“It may have something to do with the current situation, I don’t know. However, in the past we’ve seen that times of financial troubles have given our organisation more members,†Habbarstad says.
All-time growth for Trekking Association
related article: When the going gets tough, Norway’s ‘tough’ go hiking
besthike.com 
This is noticeable in Australia. When times are “good” people work long hours and fly half way around the world for tourist type holidays, so not much hiking. In poorer economic times they have greater leisure time and want cheaper holidays so hiking is popular. Some of the best holidays I’ve had are the cheapest.