Why plugin and not component: Authors must be left to take their design decisions. Users can report only usability and their liking here.
Thanks...the broken link is fixed. Also, if you would like to see some more complex examples, please take a look at the Quick Start page for the gCalMarkup extension which uses sdMacros extensively: http://symmetricdesigns.com/joomla-extensions/gcalmarkup/quick-start/configuration.html (http://extensions.joomla.org/extensions/calendars-a-events/events/events-calendars/14645)
This extension started on the wrong direction. How can it be a good extension then?
Well, it can be a good extension if it's useful, well written, and well supported:) Actually, a component was briefly considered, but didn't seem to give much, if any, advantage for the increased complexity. There was little reason to create an entire management component when the existing article infrastructure works perfectly for this. This may change as features are added, but currently there is nothing that requires a component. sdMacros is still in beta and I'm open to suggestions. If you see advantages to having a component, I would appreciate you posting them in the support forum. sdMacros has proven very useful on several of our websites and I suspect it will prove useful on others' sites as well.