If there's one card which is rather pointless to discuss in pre-prepared strategies, isn't it embargo?
I'd definitely agree that it doesn't lend itself well to very quantitative discussions. It depends a lot on how the other player reacts, and there are definitely a lot of good and bad ways to reacting to it, as well as psychological biases.
But I don't think you can play a card correctly if you don't discuss it to some extent, if only to have seen scenarios and dismissed them. Even if Embargo is unplayable in 95% of the cases, you might want to be able to recognize the 5% where it has some use. If anything, the fact that the card and its consequences are quite opaque (in terms of tempo for example, it can cut both ways. In terms of end condition too, given that when you double embargo provinces, the person buying provinces after the curse pile is empty has a huge advantage) means that is should have higher room for better playing than "vanilla" cards like smithy/witch...
Granted, I'll be the first to admit that every time I play embargo, all I see is variance increase to the point where I am unable to see if there was any modification to the mean.