sparkfun is not carrying it so it must be not popular
And that is the sad truth.
But one more counter point, I think this is a case of the interest isn't there because the product isn't there. The cart before the horse, or the chicken and the egg dilemma. I look forward to Sparkfun's new product post every Friday because there is occasionally that thing they put on there that makes me wonder what I could do with it. I think this is one of those things.
So I have been digging a little more looking for a mini wired generic keyboard on alibaba with some limited luck.