This link from 2011 shows some of the past users entries into a monthly Design Challenge Cadsoft had.  The forum was full of submittals at that time.

Envisioneer Design Challenge Competition Entries 2011 – YouTube

All I can think of is that new uses have a ton of online you tube Cadsoft created videos on various topics.

They also have better customer support / training and even promote Design / Drawing and 3D services. So as a company they are taking on more of the load.

Why all the ‘old’ users disappeared is beyond me.

Jack