The Sigil said:
Ah... so you mean the moment I step OUTSIDE the Core 3.0 rule set.

When I see "3.0" I think 3.0 PHB, DMG, MM.
No, it's just that in Savage Species that the flaws are most obvious.
True enough, those are in the MM. However, it still doesn't solve the problem of "using as few parameters as possible"

.
Your mistake (and Mike's) is in thinking fewer parameters are possible.
Mike gives the following parameters for describing a weapon:
* Name
* Size
* Damage
* Critical Multiplier
Now, let us build the types of "swords" possible with this:
Needle - Diminuitive - 1d3 - 19-20/x2
Dagger - Tiny - 1d4 - 19-20/x2
Shortsword - Small - 1d6 - 19-20/x2
Longsword - Medium - 1d8 - 19-20/x2
Greatsword - Large - 2d6 - 19-20/x2
Fullblade - Huge - 2d8 - 19-20/x2
Bigblade - Gargantuan - 4d6 - 19-20/x2
Whoppingblade - Colossal - 4d8 - 19-20/x2
(Damage codes are probably wrong, but you get the idea).
Now, take an Ogre rogue. What weapons did he have proficiency in?
Take a Cloud Giant rogue. What weapons does he have proficiency in?
Take a Pixie rogue. What weapons does he have proficiency in?
At this point, one begins to see a problem with the system: The D&D 3E Proficiency System primarily works by the NAME of the weapon. The size is irrelevant. The rogue, who should be able to use various weapons allowable to them, can't, because only the man-sized weapons of those type are allowed. (The Simple/Martial/Exotic system doesn't affect the argument at all).
Indeed, a Colossal creature CANNOT use a greatsword proportionally sized for them, because no size code exists for it! This is, quite simply, stupid.
If we do allow the resizing of weapons, (and allow a halfling to use a rapier proportionally sized for them with Weapon Finesse), then you get the problem of the wizard using a Large Dagger. Hmm. Another problem.
Well, then why not adopt the 3.5E system of having a -2 penalty for each size difference from what it should be? At this point, the 3E system falls in a quivering heap.
What size should a dagger be for a Titan? You need to remember that the Titan is a Huge creature, that a man is a Medium creature and that the man-sized dagger is Tiny (and thus two jumps down), and then Huge -> Large -> Medium and
then you realise that the dagger must be Medium for the Titan. When you start moving to stranger weapons, the calculations are absolutely horrible.
Cheers!