I was attracted to this discussion because that's an argument I'm trying to make in a short story I'm currently fixing.
I think it's pretty easy to come up with contexts in which self-interest is good, because it aligns with morality (ie doing something that is both beneficial to you, to those around you, and perhaps to humanity as a whole). But as long as self-interest and morality coincide, there is no conflict, and therefore no story.
What's harder is imagining a context in which self-interest battles it out with morality (which is what the dynamic pair in the Dramatica pattern dictates), and self-interest still comes out on top.
My take is that you can play with the different levels of "others". Sometimes pursuing your self-interest is beneficial to both you and your inner circle, but not to humanity or the world at large, or vice versa. I don't think anyone can make an argument in favor of self-interest without taking into account the benefits for some others. The whole question (and where disagreements arise) is which others. I once read an interesting article about a conservative thinker, which summed up the difference between conservative and progressive thinking patterns pretty much in this way (conservatives favor close others, be they family, locals, or their country; whereas progressives usually think in more global, quantitative terms: what benefits the most people?).
You can also articulate self-interest vs morality in terms of means vs end. In my story, the MC is determined to kill the big bad tyrant to take his place. His argument is that a person more concerned with morality, and with less personal ambition (ie self-interest), wouldn't have what it takes to seize power in such a context. Either they would balk at the idea of killing their opponents, or they wouldn't make the necessary compromises to garner sufficient support.
Now I'm not trying to paint this in a super positive light either, but simply as a (possibly) more realistic step towards something good than, say, an overnight revolution of everything. Kind of like "a bird in the hand is worth two in the bush".