I simply can't understand how someone can really defend such thing by now. It was pretty much a viable, if not preferable, hypothesis, before the emergence of all the molecular data, but now... impossible. Unless we're allowed to make really crazy ideas about how pseudo-genealogical patterns of acquisition of RNA viruses could happen and things like that.
At the same time, that does not mean that all the similarities are meaningless, actually, some people propose "alternative" hypotheses that take these evidence as more relevant than just the bare statement that chimps and gorillas are more closely related to us.
For some people, bipedal apes came first, as bipedism is/was somewhat already present in arboreal apes, which are the ancestors of both the lienages of bipedal "apes" (australopithecines, humans, etc) and knuckle-walkers (gorillas and chimps). Then instad of bipedism being an "evolved" trait of our lineage, it would have been just a betterment of secondary bipedism of arboreal apes, while knuckle-walking evolved independently on the other lineages. Some people even propose that chimps descend from Australopithecines.
The overall "humans retained and improved secondary bipedism" is a rather old hypothesis, actually, but it's being "revamped" recently by some researchers.
And how does that connect with the evidences that Schwartz (and hopefully no one else) cites to defend that orangutans are our closest relatives? Well, basically it would all have been inherited from a common ancestor between humans, chimps, gorillas and orangutans, along with bipedism, but lost in the lineages of chimps and gorillas.
Some old school theorizer of that idea (I don't remember his name, I guess I read about it in "Lucy: the beginnings of mankind" by Johanson and Edey or "the ascent of man" by Pilbeam) proposed that it happened due to some sort of "evolutionary pressure" that lead the other African apes to diverge from "pre-humans" (while the orangutans remained "safe" in Asia), a sort of selection for "character displacement".
I think it sounds pretty convincing overall; not only the knuckle-walking seems to me to be more plausible to evolve twice than full bipedism from knuckle walking, even if only once, but many other things seems to be coming together with this idea recently (or at least I had this impression from a few news along the last years, that seemed to fit together).
And I also think that something similar perhaps happened with lions and leopards, which, despite of being more closely related to each other, are far more physically/adaptively different than lions and tigers. Which, of course, is not an evidence per se that the same happened in the apes case, but a whole different episode, which would only illustrate that perhaps this thing could happen at this continental level. But that's just my layman's guesses, anyway.