nothing wrong with wanting to be helpful.
But I do think that if you're an advocate of something that is particularly emotive, ie breastfeeding/weaning (and there are other very emotive issues re bringing up children ie smacking/controled crying/co sleeping/putting in own room and the list goes on), and your motives are to provide help and accurate information where possible, then it is important to recognize that not everyone has those motives and that there are some who wish to judge/preach, and to disassociate oneself from those.
It's a bit like religion in that sense IMO. There are people who believe strongly in their faith, and who wish to use that faith to do good, but by the same token there are people who use their faith to look down on others/to tell them how they will be going to hell if they don't repent etc. And for the most part, the former do not wish to be associated with the latter.
Similarly with these issues I think that the informative need to be as scathing of the judgemental as those receiving the bashings, thus reinforcing their position as informer rather than judge/jury.