If Kajiya, Lane and Riccetto get roles that, absent the height of these ballerinas, would be accorded to other soloists or corp members by merit, then is it right to prioritize finding a partner for short men over the advancement and development of other ballerinas? Why don't the taller women who might now be losing opportunities get priority and, when they get roles, cause non-short men to be cast next to them? Why the male development focus?
A related issue is why ballet adheres to the traditions that that male danseur is expected to be taller than the ballerina. Is that something that audiences should reconsider?
I don't think that male development is always the focus: it goes both ways. I would venture to say that Cory Stearns has received certain opportunities because his height allows him to partner some of the more established taller women such as Part and Wiles.
Height is not merely a matter of aesthetics, either. Women grow several inches on pointe (taller girls grow more, as they have bigger feet). Often the male dancer has to hold the female dancer's arm above her head to support her in assisted pirouettes and promenades (I wish I could describe this better, but hopefully you know what I mean). This could be difficult and tends to look really awkward if she is already taller then him on flat ground. (Just imagine someone is taller than you and you have to hold one of their arms over their head while they spin around in front of you.) Also, there are lifts to consider. Gomes can partner anyone, but Simkin, as one can easily see, is somewhat limited as to whom he can hoist over his head.
It does seem unfair: a small ballerina can be partnered by a tall/big guy (like Boylston and Gomes in EHAO or Julie Kent with Roberto Bolle) but generally a tall ballerina doesn't work with a small guy (because of reasons I mentioned). Of course there is some choreography that doesn't call for pointe shoes, or doesn't call for much partnering, where height doesn't matter much. Or even some--Prodigal Son comes to mind--where a taller girl and smaller guy can work to great effect.
I love watching partnerships develop and evolve; it's one of my favorite parts of ballet. I'm not sure if Reyes' was promoted mainly as a partner to Cornejo; I recall that Julio Bocca and Angel Corrella used to partner Reyes fairly regularly as well. (Of course Bocca retired years ago and we see little of Corella these days) She may not be a technical virtuoso like Murphy and others, but I always admire her acting and musicality. I've come to appreciate her more and more over the years, especially her Giselle and Juliet.
Incidentally, if you're interested in a parody of the classical ballet paradigm you should check out the Trockoderos. They love to play on the big ballerina with the small male dancer theme. It's pretty astounding some of the partnering they actually do pull off, but you can clearly see (and get a good chuckle at) the difficulties that arise. They will also provide an answer to your pointework question.