If you thought that in the first place, you weren't much of a leftist to begin with in my eyes.
e: Also - I want to be clear, variance is incredibly high even where there is heritable signal. The notion of X "can never be an astronaut because her genetically defined brain structure" and also her children is just not anywhere near supported by the evidence.
Obviously the groups that will have the hardest time with accepting something like this are the groups that say things like "It's not your fault you didn't go to college, it's [insert social structure] and therefore our entire mission is to change [social structure]."
What does "deserve" have to do with anything? We're not in kindergarten, this is the real world. If she is capable of being a satisfactory astronaut, then give her the job. And if she is not, then don't give her the job. Whatever benefit it is you think the job bestows, whether that is a high salary or some level of prestige matters not at all.
This isn't hypothetical, we're starting to see this as a real problem in professions where the success of our country and government (and for everyone who lives within it) depends on our ability to ignore asinine "deserves" arguments.
Regardless "linchpin" is a bit much