Some people perceive that it is difficult to make a living in the arts. Could this have something to do with the demographics of those attempting to do so?
That is part of the problem. We know women make less money then men for the same work, and we know minorities are over represented in the lower levels of income, and we see strides to correct those issues as progressive positive societal efforts.
Surely, we cannot say its their fault for earning less or being poor and thus have less choices when it comes to the path to personal fulfillment (or whatever other reason someone decides to go to art school).
Why then not see the problem of under representation of minorities in art schools and women in the arts in general as an extension of the above problem, and strides to correct it (even if merely by acknowledging the fact it is so) the same progressive positive effort?
Blaming the poor for being poor because they do not work hard enough does not absolve 400+ years of systematic and legal disenfranchisement. Yes, it is true, some take advantage of such progressive positive changes to better society for the greater good of all, and that is a small price to pay if it means these in built inequalities discussed in the OP's articles are even slightly alleviated.