One: people will always find something to complain about. That's how people are.
Two: phys ranged wont suddenly 'become the best' if they're allowed to be competitive with the melee and casters. Mechanics that define the job will say who is best and who is not, and if yours doesn't align with the situation, then you're not the best. Right now, even if the boss favors a phys ranged job's mechanics, it's still the inferior choice because simply existing as a phys ranged means you do less damage because of an antiquated system that hasn't been updated to the current era.
Third: Why should playing that role punish the player for that choice? To know that your best effort is a half-assed effort of someone else? Because you've talked about maximizing samurai, would it be fun to do that and know that some floor tanking dragoon did more than you because they could manage to push buttons? Doesn't make for a fun time when your effort isn't rewarded. For the phys ranged, it really isn't right now. We want to be competitive and useful, not relegated to token role or completely cut out because our only worthwhile contribution to the raid is a groupwide damage reduction. Like sure, fantastic, but even a caster gets one that works specifically for magic damage, which a majority of the killer attacks are magic based.