I concur completely. Back in those days, the very basic stuff you mention (awk, sed, make) were being built by a handful of people, all sitting together, and the few outsiders who were submitting enhancements (even before these were called "patches") knew the email addresses to send these to. For Sendmail, you should contact the people at Berkeley, for most of the others you sent to Bell Labs.

Then software started appearing from other points. We were getting new versions of software after email announcements -- and later on, on comp.sources.unix -- and we were reading the comments to see that other people were contributing, too.

The way you publish your software (especially today) essentially boils down to how much you are looking for contributors vs. users (vs. no one at all).