What they're trying to say, using the usual feminist sociology over-loquatiousness is:
For some on the planet, keeping it under 2 degrees will preserve a relatively familiar or at least acceptable quality of life.
For others on the planet, quality of life can only be preserved by keeping it under, say 1.5 degrees, or even one degree.
The first group (that can live with a higher threshold) are those in the upper portions of the global economic scale, and it's an acceptable rise for them because they can also afford technologies and tools (getting crude, say, air conditioners, new home materials, new kinds of agricultural output, etc.) that make a 2 degree rise tolerable.
The second group (that can't live at the 2 degree threshold, and really need a lower one) are going to tend to be in the lower portions of the global economic scale, who won't have access to the technologies and tools that make a 2 degree rise livable for those at the top of the scale.
Policymakers and scientists tend, by virtue of their privileged position, to be in the first group, and have thus set the 2 degree rise in connection with thinking of their own, best-case lifestyles, rather than—say—a member of one of the globe's largely impoverished equatorial populations without access to much in the way of resources, tools, or technologies already.
It's a good point: the effects are not uniform, and if 2 degrees is the upper bound for the people who are the globe's *most* comfortable, then it's probably a bad upper bound in general, because it will "cook" (even more than already occurs) those that are the *least* comfortable.
It was, however, bad language and clarity—which is a sin that social science commits far too often.
Their point is well taken: