Gotta disagree with you there as I've whipped around a "Long Sword" (actually a Sudanese sword but it has the same balance i.e. made for slashing). If you and I were at engagement range with sheathed weapons and I were armed with a dagger, you with a Long Sword I'd have my dagger in your gut before you had a chance to unsheath your sword. GURPS reflected the speed issue by requiring someone to "Ready" a heavy weapon for one round before using it (Gurps uses 1 second rounds). You ask a member of the US Fencing team if speed matters and they'll tell you that it definitely does.
The Two-handers I've seen were made for slashing, piercing, AND bashing. Usually the end third of the blade is sharpened, both for using as a spear-like weapon, and for hacking the heads off of polearms. The bottom two-thirds was left relatively dull for both grip (usually with glove) and for using in a clublike manner. Even the guard and grip were used in some sword techniques. It wasn't a large clumsy slashing weapon, it is a large weapon that, when ready is only marginally slower than a dagger wielder. Slower, yes, but not in the huge disparity that 2nd edition claims.
Also, being "ready" should have nothing to do with weapon speed in combat. You don't have to draw the weapon each time it's used. The speed to recover is balanced by the reach over a dager weilder. If a user had one strapped to his back, limbered up, sure, the dagger weilder would have a dozen strikes in him. But the dagger weilder would need to be skilled to get within range of a two-hander weilder or risk getting stabbed (not slashed) with the point. The en guarde position of a two-hander is not dissimilar to a short spear.
And speed would matter to a fencer because fencing weapons are still comparable. Rapiers deliver quicker, deeper strikes, but don't favor powerful strikes like a saber would - but I have no qualms with saying a rapier is faster than a saber either. Also, a Rapier DOES have reach over a saber, from the ones I've seen.
How would you compensate for reach in speed factor anyway? It's certainly not a nonissue, because the two-handed wielder will always get the first strike in. If you did anything, I'd link weapon speed somehow not to who struck first, but the number of attacks in a round that you would get. The fastest Zweihander wielder will still only get one thrust in for every two or three of a skilled dagger wielder.