In that sense, that it is something that in a perfect world should not happen in nature - yes, it can be considered an error.
However, what I'm arguing against is using this argument, and especially the breeding one, in a discussion about "do you think homosexuality is wrong and thus it's justifiable to hate on it".
I've seen this argument a lot "you're gay and you can't have kids so you are a nature freak!", but people who say that are forgetting that
a) gays can have kids, they just need to have sex with someone they don't find attractive (and many do this, because adopting kids by homosexual couples is still a big no-no in many countries),
b) the science make it possible for you to have kids even without having sex,
c) there are many heterosexual people that can't have kids (infertility) or don't want to have kids.
Taking the nature error even further, nowadays people are born with lots of "biological errors". I'm a short-sighted heavily stuttering left-hander. I'm sure that if I was born few hundreds years ago I would be considered a nature freak. Even few decades ago, here in Poland, parents and teachers were still forcing left-handed kids to write with the "proper hand" because they thought that being left-handed was simply wrong. Thankfully it's not the case nowadays and I hope that in the future people will stop condemn homosexuality.