The failure mode there was that people could get subscribed by
clicking on a link but there was no button on their mailer to
unsubscribe. So list managers go lots of "get me off this
thing!" hate mail because people got subscribed without learning
the ropes of manipulating their own subscription by mail (which
is more fiddly and takes more training).
This did not mean that there shouldn't be clickable mailto
anchors for lists. What it means is that this click should
activate the email to the potential subscriber of a list
prospectus that they have to act on by mail. Then they
understand what they are getting into and the screams downstream
are fewer.
Coalescing on a common UI, and ease in moving among communication
modes are ergonomic imperatives that are going to happen.
In the historical News [etc.] UI the paucity of the UI meant that
one had to memorize commands and netiquette. In the
consumerization that started with Mosaic bringing the Internet to
the masses, various of the things that were memorized by the News
user or yore need to be spelled out and folded into the process
in the way of overt cues, advisals and confirmation requirements,
so that a rank newbie can navigate the process sure-footedly by
paying a modest amount of attention. The GUI gives you the
display bandwidth so that can be done. We just have to remember
what it was that we had to remember, and make is so people get
told now and don't have to remember...
Al Gilman
Example: you don't subscribe _anybody_ to a newsgroup without a
confirmation, and enough advisals so that few people don't know
that they did it.