There are several possible solutions to this conundrum, the main one (the one I always used as a young DM) being: "Who cares? She's a monster, it's an adventure, so go kill her."
However, as an older (and perhaps more anal-retentive) DM, I now find this solution less than satisfying.
A much better solution I found through Grodog's Greyhawk site, that the Eilservs, being all crafty and wise, actually are somehow working to misdirect the adventurers into the false belief that Lolth is behind the giant attacks. They hate Lolth, want power in the Vault over her priestesses, and so want to destroy (or weaken) Lolth by using the PCs as a tool to this end. I like this, but in many ways it still leaves me cold. Does this mean that the entire epic adventure in Q1 is nothing more than an anticlimactic misdirection? Does this mean that Lolth (with her godlike wisdom and intelligence) is somehow unaware of these machinations and is, essentially, being outmaneuvered by the Eilservs? Does this mean that the many sacrifices the players will ultimately make to conclude Q1 are all for naught?
It's questions like these that led me to try creating another possible link between D3 and Q1, an overly-complex one, perhaps, but nonetheless workable.
What if the Eilservs were, indeed, attempting to lure the PCs to the Vault, to use them to weaken the Fane and Lolth but that, moreover, Lolth was still, in fact, behind the giant attacks all along? There are all kinds of clues suggesting the Eilservs want the PCs at the Vault -- the "accidentally(?)" dropped map of G3 being the main one. The "Misdirection Hypothesis" has legs. However, what if the Eilservs' knowledge of the situation was incomplete? They believe (according to notes in D3), that they want to grab power in the Vault, to become the undisputed temporal rulers of the Drow, and that the Priestesses opposed them at Lolth's bidding. So, the Eilservs turned to the Elder God and tried to set up a surface realm through which to gain power that they could then use to dominate the Vault over the objections of the Priestesses (and Lolth). That's pretty specious reasoning, by the way: why should extending yourself into the upper world not tax your resources rather than enhance them -- perhaps in the VERY long term such a tactic would hone the Drow in a survival of the fittest kind of fashion and (in accordance with game mechanics) provide experience? Regardless, I'm proposing that, for some reason, Lolth wanted the Eilservs to turn from her and reach out to the lands of the Sun. But why?
Asimov's "Caves of Steel" series provides a kind of answer. There, Daneel Olivaw does not save the Earth from radiation poisoning but, instead, foresees that forcing people off the planet through increasing the radiation is the only way humanity will ultimately survive and flourish. Could Lolth be thinking something like that? Perhaps she reasons that the Eilservs' grab for power, even if unopposed by the Priestesshood, would send the Drow into a protracted civil war, a continuation of their feuding ways that has, up until this point, disabled them from ever launching devastation sunwards or from accumulating any real power for themselves and her. Perhaps, knowing full well that her Chaotic Evil minions could never act in unity, she forces out her most promising children (the First Ranked House of Eilservs) to fight and flourish (if they can) in the testing ground of the upper world. If they survive and gain power, that, she might think, is a good thing. Yes, they have turned to the Elder God but he (she? it?) is a notoriously neglectful being (if we're talking about a Lovecraftian God, I'm surprised Eclavdra can even cast spells). If Lolth is looking at the long term (she is immortal, after all), perhaps she knows that these renegade Drow will inevitably fall back into her fold after they tire of being ignored. In short, maybe Lolth opposed the Eilservs bid for power in the Vault because she sees the resultant war (even if the Eilservs are victorious) will only force her children to be more insular. She ultimately wants to see them thrive and expand, knowing that their gain in power will ultimately be hers. Therefore, when the Eilservs "misdirect" the PCs into thinking Lolth is behind it all, they don't actually realize that she really is behind it all -- the quest to kill Lolth is valid and even necessary to preserve peace in the upper world.
Of course, there are all kinds of holes in these ideas: why doesn't Lolth just appear in a shower of gold and tell her children to stop squabbling and march to the surface? I can't explain that except by referring to the chaotic evil nature of Lolth and the Drow -- the former works by misdirection because the latter despise being told what to do. There are problems, but I just know I like this kind of flaw better than the idea that the Eilservs are somehow outsmarting Lolth and that the tribulations of Q1 are all for naught.
I'm quite sure EGG would laugh at all this: why do Lolth or Eclavdra need the kind of motivation that WOTC ascribed to Zagyg in "Expedition to the Ruins of Greyhawk" -- motivations EGG scoffed at in his "Upper Works." However, I have essays to grade and need some displacement activity, so . . . can anyone collaborate with me here and help iron out the kinks in this little narrative? That or supply another one that makes some (more) kind of sense? Allan, I'm specifically thinking of you (as I believe you still check back here from time to time), but I'd like to hear from any interested party.
Cheers.


