They didn't have publishers back then, so why would they need them now
You don't need a publisher when you release something to be distributed for free, just like back in the days. Like I said, the PD houses plain ripped off the demo scene, and very, very few groups actually wanted the PD houses to sell their works.
(edit)A good comparison in modern days could be selling books made entirely out of wikipedia articles (which some companies actually do).
Sorry but publish means to publicize and the PD houses did just that. You do need an outlet for your creative works. The world of today is internet based and very different. The point being that the various Amiga groups were very remote from other community groups. They were enjoying their creative demo making and wanted not only to share their work but make themselves known. The PD Houses were the outlet for that work and they took the base demo and then labelled it with their own PD logo and then published the lists in the various magazines. They were publishing the works. You would need to buy the actual disk from the PD House to enjoy the content. And only when you put the disk in the drive and let it run would you see who was responsible and who created the disk.
As an aside... if you go through a lot of the 17-bit CDs you will see great gaps in the listings. That is because disks like say the Miller Lite demo were removed for fear of copyright issues. The PD House who published both the disks and CDs were very worried of being taken to court.
So you see the PD House being the publisher was reponsible for the circulation of the disks and also took legal responsibility. There was nobody else publishing the work.
As for today, the world is a very different place and yes you can promote your own work and hope to gain popularity that way. The issue is still a simple one.... back in the day of the demo there was no real social networking as we have today, the computers were in their infancy and users were pretty much absorbed in their computer activities. The demo was used not only to promote the individual but also the creative strengths of the computer. Demo makers were trying to push the boundaries out and in doing celebrate the fact.
Today most that use an Amiga do it for the fun aspect of using old technology. It also lets those that once used the kit to enjoy memories of their past. The demo does not have any real relavance today and I doubt there are many that actually refer to them for new and inspiring stimulation. I applaud anyone that creates anything with the Amiga these days. The well is sadly pretty dry in truth. There isn't a day that goes by that I do not use my Amigas, and or involve myself in the community in some way. However, I hold to the view that the Amiga is of the past and dwells in the present as a symbol of a better time in computing, when, there was an active user base with real purpose and dedication. Nothing like it has ever been replicated and never will.
Enjoy your demo making, I do look forward to adding any Amiga related works to the collection. I do love the Amiga and will always love the Amiga. Still a great source of joy.
Not sure how big a demo collection you have but would certainly recommend you get hold of a few of the MASH disks and read all the contents on the disks and read fully the intros on the numerous demo disks to get a good understanding of how the way the User Groups were interacting with the demo creators. You appreciate no doubt that the demo was generally only one part of a larger Mega Demo as they often called it so you have various levels of activity. Fantastic stuff I have to say... and for me I am thankful of all those PD Houses cus without them I would have nothing. How else would the work have gotten into circulation. I am very lucky to be able to help folk wanting disks, and trust me they always refer to a PD House reference.
Good talking to you... back to the demo library listing... playing a rendition of Smooth Criminal at the moment. Cool.