I read a nice list of interesting web comics and decided to check something out. After I sorted through the ones that looked interesting, I realized something. If something doesn't have the RSS feed, it's useless, with a few exceptions.
I use Flickr without RSS feeds, but that's because every few minutes something happens on the site and I have tons of contacts and groups. So, even though Flickr has tons of RSS feed options, I don't use them.
I think, pretty much, the rule is, "Unless your site is so interesting that I will want add it to the list of about 10 sites I'll check manually, you need an RSS feed to the piece of information I want."
But, back to the web comic list... I decided that I wouldn't add any comics that didn't have an RSS feed. Which is hard, because most web comics don't have an RSS feed.
I think the problem, from the artist's perspective is that the business of web comics has traditionally demanded that you visit the page and view banner advertisements in order to make it an even mildly break-even proposition. And since this is the perfect sort of content for people to do antisocial things like hotlinking individual strips, they generally prevent you from doing too many outlinks. So I think the biggest fear is that people will view the feed and not the link.
Which is, of course, a load of crap. I can specifically call out Kukuburi because they have the lowest possible useful level of functionality on their RSS feed, but still enough to work. All it does is let me know that the comic has been updated, which is really all that I need.