I won't dispute a native Fencer trait, the fact that we don't have that is simply asinine.

The reason I support all-jobs Dual Wield is because its so bloody useful. Whether your intent is damage, magic potency, or stat boosts, everyone can make good of it.

NIN might be the first thing everyone thinks of when mentioning the trait, but let's not forgets this is FFXI, and NIN isn't the only job with the trait. But NIN's identity isn't damaged if everyone got a Dual Wield 0; both NIN and DNC would still have the higher tiers. Their identities remain untouched.

For RDM, it frees up the job's sub-options. It leaves you to decide whether you want NIN for shadows, DNC for Sambas, or DRK for whichever reason you prefer... and so forth. Additional powers to main classes can expand sub job novelty; giving everyone Dual Wield frees up RDM to explore sub jobs that bring a little more to it's melee--and giving additional traits to the job (such as a native Double Attack), might allow for even freer exploration of sub jobs.

And like I said, the only aspect of RDM that would see trouble is En-spell 2 and let's admit: it's already stagnant. Assuming an all-jobs native Dual Wield and the threat of RDM, devs could simply remove the building damage component of the spells, and cap it at somewhere reasonable. It could still be made useful without giving RDM an unfair edge.