You could say the same thing about Nixon - he was a paranoid, anti-Semitic sociopath, but he created the EPA and tried (but failed) to pass healthcare reform and universal income.
"Truly evil" doesn't mean anything objective, every President I can think of is or has been considered truly evil by some significant segment of the American populace, and many have probably been more evil than people are aware of.
What would matter is what Zuckerberg's policy agenda was, whether it would benefit the US and whether or not he could be effective in passing it.