Yes, while it is true many supervillains come from an educated background, it is not a hard rule. Many villains are also grunts and come from non-educated backgrounds: gangsters, mindless monsters, etc. It only makes sense that the educated villians achieve supervillain status, because they're the ones who are smart enough to organize a following and push their sinister agenda. But it's important to note that it's their actions that make them evil, not their education.

Both heros and villains have their leaders and their grunts. The leaders usually have the educational background needed for keeping an organization together. The grunts usually do not, so they end up doing all the dirty work.

I offer to you these counterexamples:

Undereducated Villains:

Overeducated Heroes: