There is really not much of a point to giving control to remove subscribers from the list, as they can simply resubscribe again.
@markel, Ryan, just pointing out that what you say is also valid for confirmed email subscribers as well, but on that list blog owners have the option to remove the subscriber.
The only sploggy/spammy thing about this particular subscriber is their URL; they've never commented on my site, that I remember, nor blogged on their site, so it's not cut and dried whether they are truly a splogger or not. I'd just like the ability to remove them from the subscriber list.