Your two fictional quotes are vague enough for subtext to creep in, but the quotes in the article are quite plain and clear. Speaking to reporters (especially foreign ones) is one of the few cases where Japanese people feel free to speak frankly, because there is a significantly reduced feeling of social judgment. They generally won't talk within their social circle about causal sex because it will lead to talk (or more likely implication) of marriage, which is an uncomfortable subject nowadays, for reasons outlined in the article.