A good debate is always healthy, but I have seen many cases where there have been comments along the lines of "that's just stupid" or "that's the dummest thing I've ever herd". When the "discussion" devloves to that point, then it has become a personal attack.
And a lot of times they ask the OP "who or what is your source" and they rip the OP if they can't produce the name of a high-ranking Disney insider. In my business I know more about what is really going to happen from the sideline people than I hear from the main sources and yes, it usually does end up being true!