I've done a bunch of original designs, and even my recreation costumes tend to be obscure so often people don't know what I'm from anyways.
I love seeing awesome costumes regardless of whether I recognize the source; I constantly go up to cosplayers/costumers wearing cool things and ask them about their costumes.
I know that a lot of anime cons are biased against original designs (and in some cases have rules against them), but sci-fi, fantasy and media cons are usually much more welcoming. I just came back from Costume-Con
and saw tons of amazing original costumes.