SMN - Why it is not a very interesting job and not a good upgrade from ACN

[Borfin]

In FF3, Evokers had White/High Summons and Summoners had... just Summons.
In FF5, Summoners - you guessed it - primarily Summoned high-damage AoE attacks. Sure you could give them Black Magic, but that was true of any job. FF6-8 didn't have a specified Job, but I can't think of any Summons that inflicted Poison or Sap or whatever depending on the installment. Even if they did, they were rare.
Tactics? Offensive element-based summons with a focus on burst.

XII shifted eidolons from silent protectors to fallen angels hellbent on destruction, so that's a point for the other team, and I can't comment on X-III as I haven't completed it entirely.

Eiko and Garnet both primarily used Summons offensively (Eiko got Holy but that wasn't until the end of the game), Yuna's Sphere Grid is entirely white magic until she cheats and borrows from someone else's. I must have played differently than you, because I recall using aeons on nearly every boss fight both offensively (Grand Summon, etc) and defensively.

Nowhere is death and decay the theme. In fact, I would argue the opposite - Rydia, Eiko, Garnet all are capable of white magic at some point in their games, whereas only Rydia is capable of casting decay-themed spells.

I'm also kind of sad I won't get to cast Hellfire, Judgement Bolt, or Diamond Dust. :P

There is a recurring theme that Summoners depend on their summons for their damage output.

That is no longer the case.

Now it is based on magic the summoner wields (which is different from abilities the summoner uses, note the distinction) and NOT the power of the summon he controls, particularly with a focus on decay and disease.

This irks me.

Again, I love the job - but the sudden shift in thematic design is very jarring. It makes sense for an Arcanist I suppose, but I disagree with it matching the theme of the Summoner.