It's not just motorcycles. There were lots of car magazines, now just a few. When I was flying more, decades ago, there were racks of magazines to choose from at the airports. Now, mainly just one magazine for any particular subject. ( "guy" magazines).
I was only interested in old magazines that had write-ups about my particular bike, which I have....When I go to swap meets, there are boxes and boxes of old bike magazines for sale......
When I was young, I couldn't get enough of car, boat, plane, firearms, repair, etc, magazines......