Chances are that either you're asking for to much or the set just isn't in demand.
Inexperienced marketers don't actually get that much attention until they become good at it, i posted my first thread in the market a while back and it got very little attention.
However i put it down to bad artistry on my part.
Yea, chances are people just don't want the set, just gotta find the right buyers, no set reason though.