First, I don't think that corporations are nothing but parasites, and said as much in the article. I did say that finance was parasitical. That was probably too strong. Allocation of capital is a useful function; the problem is that the allocators are helping themselves to a far larger cut of the proceedings than the value they produce (and I don't particularly want to argue that here, just wanted to clarify what I meant).
Second, the more central point about whether the Singularity Institute types are wasting their time and should refocus their thinking. It is true that not many people are thinking about the effects of superhuman AIs, and there's no harm and possibly some good in a few smart weirdos focusing on that, especially since corporations have been around and critiqued for so long.
However, we are so far away from producing anything remotely close to that level of AI, that I fear their work is ungrounded. It strikes me as fun quasi-SF rather than serious engineering.
But I take believe they are seriously interested in world improvement, so my suggestion to them in their work on "benevolent goal architectures" is to study how existing goal architectures work, that is to look at existing economic and social systems where disparate individual goals are coordinated into cooperative or conflicting action, and how the results are related to human goals and human flourishing.
For my part, I am in the process of trying to understand their friendly AI work better so I critique it from a more informed standpoint.