captainjack23 said:You're going to need to work harder to justify that as an easy throw away answer. I think you are mistaking conservativeness and stasis for stupidity.
The Vilani did lots of things that would be considered stupid by Terrans. Heck, the Terrans got away with sheer bloody murder when they should have easily been stomped flat. GT:IW even has a big text box (on pg 29) asking how the heck the Terrans got away with it - the Terrans simply shouldn't have survived if the Vilani reacted sensibly toward them. And that box even says explicitly that it was clear that the early Vilani were very different to the ones that the Terrans encountered.
But they didn't. The Vilani social structure, inability to work well outside of tradition, and political pressures on those who tried that (which brought down your "out of the box thinker" from the 3IW) all conspired to give the Terran the breakthroughs they needed. It's likely that had it been any other culture - one more similar to the Terrans - we'd have been annihilated.
Maybe some bright (and somewhat crazy) Vilani spark did say "hey, why don't we try a DSJ"? But he would have undoubtedly been rebuffed by his superiors for daring to think of such a ridiculous idea. For no reason other than "Because That's Just Not How It's Done". Who knows, maybe if the Vilani had tried the DSJs then someone rebellious bunch further back in the 1I would have got wind of it and tried it too. Maybe the Vilani wouldn't even consider it because it'd change the entire structure of the 1I.
The Vilani had simply never faced a foe that was as adaptable and ingenious as the Terrans and more to the point on an equal technological footing to them (with their much vaunted J2 drive that they kept to themselves). And to cap it all, the Terrans managed to surpass the Vilani in a mere 200 years of development, and at the end of the IW era were running rings around them with J3 amd blowing their ships up with meson technology unseen since the Ancient era (and maybe Sabmiqys). The sheer inertia of the Vilani meant that they just couldn't adapt to it, and couldn't get their heads around the fact that the way they'd always beaten these upstarts that they ran into just wouldn't work here.