Ah, yes. That one inherits the ‘Approval’ buttons rather than the Flag ones as it’s classified as a Queued Post/Topic:
I think as that setting is specifically to catch out potential bots and spammers it would be good to have the same/similar options as the Akismet one for consistency.
Personally I’m in the ‘delete’ spammers camp 
but I know of a couple of sites who prefer to suspend instead, and if the option is there for the others I think it should be included for this one as well (if possible).