What the RCC is horrified and shamed by, the church which represents the vast, nearly overwhelming majority of Presbyterians promotes and blesses.
As I have said, I (fortunately) have no need (or desire) to defend either aberration.
Although I must also add ... I have no evidence of what has been alleged of this branch of the Presbyterian church ... other than what was alleged by Crusader.
Vast, nearly overwhelming?
If one is going to blithely lump all "presbyterians" together, there are about 50 million Presbyterians worldwide (http://philtar.ucsm.ac.uk/encyclopedia/christ/cep/presbyt.html). Much like the 70-million member Worldwide Anglican communion and it's "Episcopalian problem", the apostasy of the 2.5 million Presbyterians in the mainstream USA denomination are not reflective of the 50 million as a whole.
In both cases, a former mission field (Africa for the Anglicans, East Asia for the Presbyterians) is now more numerous and far more conservative than their godfathers in the USA. Not everybody lives in America, y'know.
And for that matter, American Catholics have the same problem, what with the US Council of Bishops saying that y'all aren't supposed to target Jews for evangelism to Christ anymore. Does that reflect the judgment of Rome? Well, Rome hasn't denounced the Bishops declaration, but neither have they endorsed it -- but that doesn't stop the American Bishops from promulgating such idiocies, now, does it?