I share something because I feel it has value, or contributes in some way to an ongoing discussion. Obviously others may disagree, but if I'm not even sure what yardstick they are using, I cannot apply it myself, even if I wanted.
I am sure I have contributed to conflict on the forum, by choosing to post material that I know will spark disagreement. The alternative was to keep silent to preserve some nebulous state of "harmony" that would probably just be disrupted anyway by someone else for less good purpose. That seems to defeat the whole purpose of a discussion forum, since learning from each other requires the relatively free exchange of ideas.
The problem comes not so much when people disagree or even come into conflict, but rather when they become disagreeable or incivil in doing so. This makes the difference between productive conflict leading to greater understanding, and the proverbial tale of sound and fury, signifying nothing. It is easy to make assumptions about someone else's intentions, and easy to assume wrong. It is better and more productive to focus on observable results: what exactly they wrote, how you reacted, and why.