"Spam" has always been a highly subjective matter around these parts.  For some people, if the sender pays an appropriate fee, it's not actually considered spam.  It's just a transaction.  It doesn't break any rules.  If we start trying to label certain types of transactions as illegitimate, it sets a dangerous precedent.  I can't speak for any developers, so you'd have to check with them to be sure, but something tells me they don't see themselves as some kind of sporting referee who needs to enforce rules based on judgement calls and "send off" offending parties.  If it's legal within the protocol, then that's sufficient.