To me, minimalism seems like a natural reaction to the transient lifestyles that people live now. A generation or two ago, many would grow up and settle down in the same town or county with 4 years of college being the most time that one spent outside their hometown. If you have a permanent home, it's easier to invest in filling it with stuff.

Today I hesitate to buy anything that I can't pack in a suitcase or wouldn't feel comfortable throwing away or donating to Goodwill in ~2 years.