Have anyone noticed that the reason why some persons post go off the topic is because they don't read the entire op writing before they reply to a thread, some persons respond to a thread based on the caution of the topic and that is why we meet up different opinions or suggestions that is not in lines what the OP points of view.
Secondly, when someone have written what you want to write in same thread you have to give off, instead of making a pointless point, I know very well that many users in forum make off topic because what I outlined.
Sometimes the op topic caption is already very captivating and such that some persons may have very good idea into such topics but then i think even the op sometimes should be cautioned or probably be seen as off topic because it actually is, i mean how do you explain the fact that what you are talking about has got almost nothing to do with that which the topics talk about because the topic is actually supposed to give an idea into what everything that would be discussed is most definitely going to be or look like but then some topics are much far different from that which they are talking about which actually doesn't make sense as I consider it misleading which eventually get some persons make the kind of replies they make that later turns out like they are goin off topic of which they aren't in the real sense of it.
OPs should try to make sure the content of their post do match the topic as well as what they are discussing such that a response to the topic would not lead to a much variation to what was actually intended leading to confliction of ideas and as well going off topics, i think has been the situation most times amongst most posters and the response they get.