Pretty much. I've had natural peanut butter on the keto diet (usually mixed in with cocoa powder and heavy cream), but I found I had a hard time fitting it into my plan.
If you really want to do peanut butter, look for the natural kinds that you have to stir up because there's all that oil on top. There should be 1 ingredient: Peanuts.
Maybe salt.
That's it.

I have started to really dig almond butter, and (when I can afford it), I pick up natural almond butter or macadamia nut butter. Both are amazing with cream cheese or mascarpone cheese.

-T.

I think those that are concerned with a "well-formulated keto diet" exclude peanuts more because peanuts are meant to have an inflammatory effect on the body and inflammation is thought to be key in heart disease etc - it's not really that you can't eat it on keto as it is high in fat and not too awful in carbs (unless you get one with sugar in)... it's up to you.