In theory, SMN is kind of a Necromancer, with attacks like Bio, Miasma, Fester, Energy Drain and such.
Also, Resurrection is a way to 'control' death. If you consider that you only summon versions of primals you've defeated, you have a skill to bring an ally from the dead...

I guess SE only named it Summoner because of the appeal the name has, and because a death-related class wouldn't suit well to a 'warrior of light'. But now we have DKN, so I don't know what to say... I'd like to see this job either. ^^