Whilst I understand the reasoning that SMNs shouldn't get a new skill if the other jobs don't it's not quite that cut and dry. The SMN can only ever have one egi summoned and they do not change on the fly (typically). If anything getting a new egi like Leviathan at 55 to use INSTEAD of another when all the other jobs get a new skill to use in ADDITION to their others would be unfair on the SMNs...

Maybe I would feel different if they bothered to balance them so we have more reason to use anything other than Garuda...