Earlier quoted context omitted.
Cross that bridge when you get there. If nobody uses, there's no problem. If so many people are using it that it attracts spam, then the users can decide how to solve it at that point in time.
Of course, you are both correct here. Spam was my first thought as well. Back in the golden age of blogging, I loved getting pingbacks on my posts, but the ecosystem became flooded with spam to the point that anybody old enough to remember what pingpacks are will automatically associate them with spam. It'd be nice if this service could address this concern, which lots of people will have immediately, and it appears…
The great thing about MovableType, b2, and eventually WordPress was that pretty much anyone could install it on a shell account and set up a fairly sophisticated publishing system. The lousy thing about MT and WordPress was that it was fairly easy to write automated tools to spam comments and trackbacks and now your unsophisticated bloggers were trying to become DBAs and understand the nuanced differences between MyISAM and and InnoDB tables and locking and…oh…it was easier to migrate to blogger and TypePad and eventually Tumblr/Facebook.