Partly it's because you're doing something abnormal - Normally what happens is someone goes and plays 2 and a half games of the Crucible, goes to orbit and comes here to talk about how broken PVP is and how could anybody POSSIBLY like it. Those people pretty much invariably have poor k/d scores. Those people are probably ridiculed unmercifully - k/d is just an easy stat to seize on. You, on the other hand... you've played enough Crucible to get a feel for it. So there's no reason your opinion shouldn't be listened to. I think probably what happens is people just look at your k/d and not your games played and make an assumption because of how often the above post (from the first paragraph) happens.