What happened around 2012~2013 in 3D printing field
A great story on the history of 3D printing is published by 3DSOURCED. It shows that the patents for FDM and SLA expired a few years earlier and the RepRap 3D printer self replicating project became very popular. Also, 3D printer manufacturers emerged and electronics, software and parts became available at a larger scale, so that it was more affordable for a hobbyist to dive in.