That was more than 10 years ago.
I think either it wasn't often used, so it didn't justify the effort. Or since 2006/2007, the VMware ecosystem has grown massively. Today you could build dozens of LAMP appliances to suit everyone. Ubuntu alone has 3 current versions out there and the Linux distributions are getting more and more.
Furthermore, the trend for such "encapsulated" applications is more towards containers and these are universally applicable and do not have to be maintained by this community.
But maybe there are other reasons I just don't think about.
OK, the Ultimate Deployment Appliance was created in 2006,
but the latest answer in its thread was on 2015-11-28,
not so long ago, I think.
However, my question concerning appliances is more general.
As I remember, on the Marketplace there were many interesting appliances created by users,
and some of them were really unique, for example an appliance named like "How net works"
created for educational purposes (probably it was a demo showing how the computer network is working).
Also, there were available virtual machines prepared for special needs,
minimized in size, containing many useful and preconfigured tools, etc.
The current Marketplace https://marketplace.vmware.com is named as VMware Solution Exchange,
and seems to be designed for VMware partners and not the community users.
So I wonder if there are still available any appliances created by the community users,
because the old URLs doesn't work.
I don't know of any such appliances hanging out there. If so, it certainly isn't a modern trend.