This is a really good article, thanks sbehmer.
I have actually been working on an article for the EA forum on shareholder activism, which I expect to be able to post within a the next week or so. I work in a related field, so I have seen and heard of various examples of corporate engagement happening.
I think I am much more bullish on shareholder activism than you are, specifically, I believe the "ReturnLoss" on share prices due to proxy campaigns can, in a significant number of cases, be negative, as it was in the Engine no. 1 proxy fight (the share price appreciated in value by nearly 50% due to the governance shakeup). I'll put more details in the article.
If you would be interested in giving me feedback on my article before I post it, let me know!
Thanks for this post. As someone hesitant to post on the forum, I would add that I am sometimes unsure if a large number of forum readers would actually be interested in a specific idea or topic I would want to write about. It might be nice if there were sub-forums for people interested in researching and learning about specific areas - that way, it would be virtually guaranteed that everyone reading the post would be interested in the content. On the other hand, it might make the space less interdisciplinary.