Rose colored nostalgia is strong in this thread.
Stop kidding yourselves because the only reason you realistically didn't use your highest grade weapons was due to one of two things:
A) One of the weapons was a multi-hit weapon, i.e. Joyeuse, Ridill, Mercurial Kris, etc., and it's all you could use in that slot.
B) You were skilling up.
Warriors used an Axe and Ridill because of TP generation and due to 2 handers being terrible at the time. The moment the adjustments to 2H weapons came to pass they switched en mass because of the massive attack and accuracy bonus.
If you used Joyeuse on a COR it's because you couldn't be bothered to buy the Mercurial Kris, not because of any "flavor". The TP generation was much, much higher than Joyeuse and dramatically offset any damage rating bonus Joyeuse had especially considering you'd use ranged weaponskills anyway.
Paladins that used Great Swords might have seemed like they did more damage because the white swings were higher, but put that same attack gear on a sword and board (or dual wield swords) and you see more damage in WS potency because of their high cap on swords that pushed beyond the native benefit of using a GS.
A Monk that used club or staff pre-proc days wasn't very intelligent because all three were blunt weapons and a massive attack and accuracy hit over H2H. Plus, there was one H2H that did slashing damage and one that did piercing damage so there literally was no need to switch weapons (plus considering club and staff WSes pre-Cataclysm were dramatically inferior).
So yeah, sure, you could use alternate weapons. The problem is those "alternate choices" sucked dramatically. I know I'm not the only one that remembers *SWORD* and board WARs trying to tank back in the day.
I concur, and you are right. However, you miss the point, which is having options. For instance, as long as you can equip a crossbow, anyone is able to use it. A THF was able to pull because he had this option available, even if his/hers main wapon were daggers. With FFXIV system, perhaps roles will be more defined, since evidently a WAR can't use anything else but an axe (at least for now). Call it Joyeuse or Mercurial Kris, it doesn't change the fact that two (or more) different weapons were available to me.