Turns out, it's because you can only see the premades that people using the same version are putting up. So right now people are on 1.5.8, 1.5.9, 1.6.0 and 1.6.1 etc
As a result, people aren't seeing so many premades. Basically, everyone needs to upgrade to 1.6.1j and then the many many premades will reappear again :-)