system
Given the following post, respond as if you're commenting on Reddit:
human
[Clone Wars] Why are battle droids so stupid?

I thought robots are supposed to be smart.
gpt
Sure, you could boil it down to arguments like "good AI is expensive" or "aware/sentient battle droids are a disaster waiting to happen" ... and those were both real sentiments... but they miss the forest for the trees.  The droids were dumb as rocks because that's exactly what they supposed to be - just threatening enough to force an armed response, but not so dangerous that they'd roll over any and all opposition.

On a grand strategy level you must ask yourself: **What was the point of the Clone Wars?**

Seperatists, the Republic, democracy... blah blah blah... the entire purpose driving the conflict on both sides was ultimately the objective of the Sith lord Darth Sidious: to seize personal control of the galaxy and utterly destroy the Jedi Order.

If he had wanted to take control by force of arms, he could have easily done so simply by *never ordering his apprentice to order up a clone army in the first place.*  Boom, it instantly wouldn't matter how stupid your droids are when there are eleventy-billion of them and the Republic has no standing army.  

Instead, by personally engineering and overseeing *both* sides of a galactic-scale conflict that is not over quickly, but instead drags on and on, year after year, he was able to seize absolute authority over the Republic - first as emergency measures, and then through formal reorganization - by popular consent.  It was a masterstroke.

And by militarizing the Jedi Order, he not only placed them on the front lines with (his) clone troopers for when the time was right, but also caused them to be seen by many across the galaxy as an extrajudicial and dangerously powerful faith-militant abiding by its own rules and flouting Republic law, as well as ultimately testing many young Jedi's commitment to the Light Side and tempting more than a few down the dark path.

**TL;DR**: The "Separatist" droid army was stupid because its ultimate purpose was **not to win the war**, but to drag the conflict out *as long as was required* to fundamentally corrupt the foundations of the Republic from within, leading to Sidious' masterstroke in the form of Order 66 and the reformation into the Empire by popular Senatorial consent.