[ddfisher]

FYI: you're probably not being downvoted because people think you are incorrect. (In fact, it is my understanding that incorrect information should generally be politely corrected, rather than downvoted.) Instead, the downvotes most likely result from the fact that a post saying only "dupe" adds nothing to the conversation. Noting duplicate articles can be useful when there were interesting comments on the previous version, but should then be accompanied by a link to that post and/or a summary of the interesting comments.

Edit: Sorry if this comes off as overly didactic: I incorrectly assumed you were new. However, my main point still stands.