If you are interested in learning more about DNS history, check out my thesis on the topic [1]. There is plenty of fascinating correspondence from the time, and interesting bouts of controversy!
This paper doesn't give HOSTS.TXT enough credit. Hostnames were invented by a woman named Peggy Karp who had this radical idea that online systems should have names instead of numbers. None of her colleagues thought of that. So she invented the HOSTS.TXT technology. She wrote the RFCs. It was the standard naming system on the Internet for more than a decade. We continue to use her work on every single computer and phone to this date. Yet she got written out of history. Not even the Wikipedia article for the Domain Name System mentions her, despite the fact she was its creator. That was likely due to rhetoric like what we see in this paper, where the guys who invented the servers for automating DNS chose to focus too heavily on the shortcomings of Peggy's system in order to gain support for evolving it.
for a few years I was a human /etc/hosts gossip agent (among other things).
I would use accounts that people had just given me at places like Goddard, Arpa, Ames and copy their hosts file. I would sort and uniq them, and go through them by hand for sanity, and then update our machines.
oh right. sorry, for completeness - there were also several well known public ftp sites .. in fact I think it may have been common to leave a hosts file at the top level. I certainly published my version with ftp.
[1] https://gade.us/thesis/naming-the-net.pdf there is also a web version