If you read the whole paragraph, it's obvious what the writer intended to convey: that health research often assumes that there is one average, representative person, and everybody else is clustered around that person in a normal distribution. The author asserts that this is wrong, because people are dissimilar in more complex ways, and instead often fall into different clusters, rather than one bell curve.

In my opinion, the author's assertion is correct; we've seen in the past that research failed to find how medication affects women in specific ways, because that research was based on the premise that people are largely the same, and thus failed to specifically test the effects on each gender individually.

The sentence people quote out of context is, by itself, confusing and weird, and thus should not have been written that way. But in context, it's obvious what the writer intended to convey, and the intent is in no way anti-scientific.