People with high social intelligence are able to drive their (often stupid) ideas through committees by using coalition-building and hate-mongering, as well as sarcasm, dismissive humor, emotionally-laden jargon ("death tax"), distraction, and a fine sense of when they can use argument by assumption. They are the people who get grants by schmoozing, playing off the prejudices of the review panel, and snappy data-free PowerPoint presentations.

Talk about emotionally-laden! This seem a bit exagerated to me.

Summarizing, the idea is that:

• high IQ -> better work performance -> better for society
• high social intelligence -> better career -> better for individual

and since a better career is a zero-sum game, it makes little sense for society to invest in that.

That makes sense, but what's unknown (afaik) is to what extent high social intelligence has (may have) positive effects not just for the individual, but also for whole organizations, society. Career success may be zero-sum game, but a organization/society with a better understanding of the social factor, may be better at reaching its goals.