It is true that breeders have a responsibility. However, when a new person comes on needing help, the simple fact is that many of them do not have the knowledge to realize the responsibility that comes with breeding. Not because they are stupid or lazy or deliberate, but because the average person (including the vets they get their instruction from) does not know it. The knowledge held by most of those on YT is not that of the average person. And when they come on here for an answer to a simple question, they instead get a host of responses about how they should not be breeding. This is not helpful, and in fact discourages them from asking anything. So the help they might have received on whelping their litter, etc.....they do not get. I cannot see how this is in the best interest of the dog.
By no means am I saying that the ethics of breeding should never be mentioned. It definitely should, otherwise these people will never be educated. However, there is a polite way of doing it that is rarely seen here.
I don't think anyone has a problem with people having concern for the dogs and breed, I have never seen anyone complain about someone showing concern. And there are indeed a great many posts which do not name names or refer to anyone individually. However, I do see a lot of scenarios like this (just a generic one here, I don't want to use anything actual):
Breeder--I choose not to bile acid test my puppies, because I don't consider the test to be accurate at such a young age.
Poster--In my personal opinion, any reputable breeder would bile acid test their puppies.
While it is true the poster is just stating their opinion, in the context it is no different than saying the breeder is not reputable. No wonder it is considered rude! How much nicer it would be to simply state their differing opinion on the testing, acknowledge that others may have a different opinion, and go on about their merry way. The poster has then educated, but in a respectful way.
And, in this spirit, I will acknowledge that others may have differing opinions.
One last thought...if a person finds that they are often interpreted as being rude, regardless of their intention, it would be the humble and courteous thing to examine their posts closely. One or two people can easily be wrong, but if a person is consistently viewed as rude by several people....could be they have a point.