That's true and many of those criteria are interrelated such as race and poverty. That said, there are a couple of points that distinguish race over these other issues.

First, the numbers for underrepresented students are pretty terrible. I spent some time doing outreach programs for graduate students, so I'll speak to that. AMS runs a survey of recent Ph.D. graduates in math and I just pulled the report for the 2013-2014 year (http://www.ams.org/profession/data/annual-survey/2014Survey-...). During that period, 920 U.S. citizens received a Ph.D. in math. Of those, 25 were African-American and 29 were Hispanic. That means that of those that graduated, 2.7% were African American whereas they comprise 13.2% of the population and 3.1% were Hispanic whereas they comprise 17% percent of the population. Clearly, there's a disconnect here, which should raise eyebrows.

As to why the numbers are that bad, it's complicated. In truth, it's hard to sell graduate school to underrepresented students since they tend to be poor. Imagine if you're the first person in your family to graduate from college with a technical degree. You can go out and immediately start making something like $60-70k/year on a job or make $25k/year as a graduate student for the next eight years. Eventually, a graduate degree pays itself off, but it's a hard sell especially with family pressure. That said, this does correlate with poverty.

In addition, there is a bias in admissions in favor of students who went to tier-1 research or Ivy League schools. Students from schools like Columbia are seen as better candidates than students from state schools. This hits underrepresented students hard in two ways. One, fancy schools are expensive and they tend to be poor. Two, family structures are such that it's less accepted for a student to move that far away from family, so they go to a state school and perhaps get a wonderful education, but they have a disadvantage getting into graduate school since they didn't go to a fancy school.

Also, as I alluded before, family and cultural issues different between races. Successful recruitment needs to be mindful of family structures and how to engage the family into making the transition to a graduate school that is likely not in their hometown easier. Candidly, we don't have good research universities in every town and family ties and values differ between races.

Now, bringing a student into a program that they're not qualified for is terrible for everyone around. It's bad for the student since it crushes their confidence and waists their time if they fail. It's bad for the department since it saps what little money they have for stipends. Good outreach programs spend their time and money looking for qualified students and encouraging and sometimes helping them to work through the process. That takes time and money, which is why these programs require funding.

As a last note, also be aware that in the past, there was explicit segregation based on race at the university level and that kind of imbalance takes a very, very long time to rebalance. For example, Rice University disallowed non whites from attending until 1964. Though, for a time, certain Asians were seen as white enough to make the cut. How long it takes to rebalance that equation is certainly up for debate and I personally don't know how long. That said, there is a moral argument that certain institutional disadvantages require rebalancing and that we may not be finished with that process.

So, yes, there are bad programs out there, but I contend there are some really good programs that have found some diamonds in the rough. Getting these students into school has been good for the community and country. Yes, this costs money. Yes, this money could be allocated elsewhere. I will contend, though, that many programs have paid off their tax dollars in spades.