Wait... So if someone reads it voluntarily but skeptically it is somehow a hostile reading by the definition you cite? It seems to me you are selectively ignoring the part where he explicitly declares voluntary reading not hostile.
You probe his definition by asking, If someone reads it skeptically but voluntarily, does that count as hostile? That's a good question. I don't think we have enough information to answer it, because Card does not state how to weigh skepticism and forcedness against each other.