Fair enough. Humans do appear to value truth.

Of course, if acts that conceal knowledge can be good because of other factors, then this:

I dunno, dude could have good reasons to want knowledge of good and evil staying hush-hush. (Forbidding knowledge in general would indeed be super evil.) For example: You have intuitions telling you to eat when you're hungry and give food to others when they're hungry. And then you learn that the first intuition benefits you but the second makes you a good person. At this point it gets tempting to say "Screw being a good person, I'm going to stuff my face while others starve", whereas before you automatically shared fairly. You could have chosen to do that before (don't get on my case about free will), but it would have felt as weird as deciding to starve just so others could have seconds. Whereas now you're tempted all the time, which is a major bummer on the not-sinning front. I'm making this up, but it's a reasonable possibility.

... is still valid.