I think people jump to conclusions too quickly, I agree that backyard breeding is a terrible thing.
However, I think there are certain situations that CAN be considered BYBing, but there are other situations that aren't BYB, but some people might consider it to be that.
If the mating is a complete accident and completely unexpected, then I don't think it's fair to shout hate at somebody & tell them they're a BYB, because BYBs actually PLAN matings whereas people with accidental litters don't have any idea & had no plan set in place, so of course it's natural for them to come and ask questions.
I think; that if you're knowledgeable to a certain extent, with enough knowledge to know how to take care of the mother and the puppies properly, then of course - breed. As long as the dog is healthy & has had all of the necessary health tests needed, and also if the sire (male) has had all of the necessary health checks, too. It's also much better if both dogs are of a high quality for their breed & meet their breeds standard.
I don't believe in mixed-breeding dogs purposely, though. Anybody that breeds mixed breed dogs on purpose is really not thinking about much else other than money or just a cool looking dog.
Sorry for your bad experience on here, but not everybody is bad & if you read between the lines, everyone really is trying to help you. Most of the people on here are really friendly and will answer you question as best as they can. You also should be aware that everyone has their own opinions here & sometimes like to share it, but don't let it get at you - as we all have different opinions & see things differently. Don't lose faith in Yahoo Answers! It's a great little community of people, that are here to help! (There are a small handful of people that just want to rant - but the majority are here to help, as this is what Y!A is for, afterall :-)
Just take everything said, with a pinch of salt & try not to take it the wrong way. I know it can be difficult, but I'm sure you'd view the answers differently if you speaking to someone face-to-face, as you're aware - the internet isn't the best place for expressing emotion!
Like I said, don't feel put off. Everyone is pretty friendly, really.