SAM out classing all other DPS

[Nominous]

SAM, on top of having 300 average more dps than DRG for the raid, also fits into any composition without being reliant on other jobs to perform well.

That is true, I can give you at least that much. Outside of NIN, SAM has the easiest time fitting in a comp, since it doesn't depend on physical weaponskills (like MNK with brotherhood), or a melee/ranged damage dealer (like DRG with Dragonsight and BRD/MCH). Also, DRG is in the worst place right now, because it depends on such specific things to bring out it's more 'support' based role they're trying to apply to it. They need a lot of love, but that's another conversation entirely.

That being said, SAM's self-reliance (in comparison to party comp) for higher damage, is a gift and curse. It makes it easier to fit within a comp, but the moment you die, you've forfeited all tangible utility you've offered to the party, since your DPS will be that of any other competing Job, MINUS their buffs. You depend on yourself, and yourself alone to bring out the utility in the Job.

NIN can die after applying TA, and the whole party will still benefit. NIN can be res'd, and still put up TA for everyone to benefit. Same for any other party utility. Since it benefits the party, it requires less personal accountability. Not to mention, we can look at the overall rDPS increase of these skills in a sustained sense, but it's important to see the immediate benefits they can have when applied. Yeah, a SAM does x amount more sustained DPS, and yes, Midare is strong, but TA is 10% extra damage from your whole party on an Add, or DPS check. TA and party buffs are going to win out for making things easier to deal with on a moment by moment basis.