Preferences for height were and are certainly not just due to an association between height and social status (and health and good nutrition). It is likely that height was selected for, and appreciated, at least for men, because increased size gave men an advantage in combat, both for mate competition and also in warfare (this during pre-technic periods of human evolution). Selection for height also includes extreme sexual selection by women for male height (which continues to this day); this preference is no doubt an evolved one, given the superiority of larger males in combat, providing protection for the women and offspring, and the ability to pass on these genes for tallness to the woman’s male offspring. Further, as has been noted in a recent book review at VDARE, given that women select (or at least used to) for male intelligence as well as height, there seems to be a general trend for height and intelligence to correlate, although of course the bell curves overlap to a considerable degree.
There are of course costs to height, which may explain why, despite advantages to being taller, some ethnies are shorter than others, on average. For example, looking at the well-known difference between taller Northern Europeans and shorter Southern Europeans (the latter, as Der Movement tells us, are low-IQ cringing subhumans), we can consider some selective pressures against height. Larger people tend to do better in cooler climates rather than in the warmer clines of the south. Further, larger people require a greater caloric intake to maintain their mass, which necessitates more calorie-dense foods. Northern Europe’s generally cool and wet climate allowed for agriculture that provided a diet rich in calorie-dense foods, such as (red) meat and dairy. In the warmer and drier south, a more plant-based diet would have been insufficient to maintain a significant fraction of the population of larger size; in this latter scenario, smaller people would have had a long term survival advantage that more than balanced out the advantages (combat and mate competition) of height. Thus, the advantages of male height are a net evolutionary gain only in circumstances in which the environment can maintain a sizable fraction of the population being larger and with greater caloric requirements.
As Sailer suggests, cancer rates are higher in the tall; it may be in part cell number as he mentions; in addition, the increased caloric needs of the tall may help fuel cancer growth through diet (there are associations between diet/energy consumption and cancer, particularly between caloric-dense foods and cancer), and increased growth signaling, particularly in the young growing stage, may prime the body for later cancer, not only by increasing cell numbers, but, possibly, by epigenetic and other changes in the cells themselves.
However, this cancer link is generally not counter-selective against height, at least not in human evolutionary history, as cancer typically is a disease in the older (Sailer’s case being one exception, as are childhood cancers and some of those due to inherited mutations), past prime reproductive age, individuals. It is a cost of height, though, at the individual and public health levels.
As to Sailer’s main thesis, why “heightism” is not a SJW issue, we must consider that Female Privilege plays a role. Milady always gets her way (Roissy being correct about the “Fundamental Premise” – females being considered more valuable, and catered to, because eggs are more valuable than sperm). Male height is a female preference, so discrimination against short men is socially acceptable. Female thinness is a male preference, so that is socially unacceptable “fat shaming” – instead we must celebrate “curvy women” – an euphemism for disgusting piles of sweaty lard, with the BMI of a neutron star, rolling around the landscape, each consuming more calories in a day than the entire world population of blue whales does in a year. When you consider that men really can’t do anything about their height, while women can certainly lose weight, the fact that an immutable characteristic is “shamed” while a changeable one is not tells you all you need to know of the raw dominant power of Female Privilege (aka, the Yeastbucket Advantage).