というものだThat is truly what one would call...
というものだ presents a considered judgment about what a situation truly amounts to. It often expresses praise, criticism, fairness, common sense, or a belief about proper behavior.
A judgment, not just a description
The expression before というものだ is the speaker's chosen characterization of the whole situation. The construction adds the force of “this is precisely what should be called...” or “this is what it really means to be....”
Praise and criticism
The standard behind the judgment is usually clear from the situation.
困っている人を見て見ぬふりをするのは、無責任というものだ。
Turning a blind eye when someone is in trouble is what I would call irresponsible.
AnalyzeThis is a strong judgment about proper conduct, not a neutral description.
危険を承知で仲間を助けに戻った彼の行動こそ、真の勇気というものだ。
His action in returning to help his companions despite knowing the danger is true courage.
AnalyzeLiterally: That is precisely what one calls true courage.
Here the construction gives emphatic praise by identifying the action as an ideal example of courage.
初対面の相手に収入まで尋ねるのは、ずうずうしいというものだ。
Asking someone about their income when you have only just met is downright presumptuous.
AnalyzeHow strong it sounds
というものだ does not normally soften a judgment. It presents the characterization as reasonable, essential, or naturally correct. For that reason, it works well when stating a principle, but it may sound preachy if used for a minor personal preference.
Evaluation versus reported information
というものだ gives the speaker's evaluative characterization: what something truly or properly amounts to. By contrast, ということだ normally reports information or explains a conclusion. The two are not freely interchangeable.
More examples
同じ仕事をした人を同じ基準で評価してこそ、公平というものだ。
True fairness means evaluating people who did the same work by the same standards.
Analyze相手の立場まで考えて初めて、誠意を尽くしたというものだ。
Only when you have considered the other person's position can you truly say that you acted in good faith.
Analyze努力もせずに結果だけを求めるのは、虫がよすぎるというものだ。
Wanting results without making any effort is asking far too much.
Analyze失敗を隠さず、すぐに報告した。それが責任ある態度というものだ。
They did not hide the mistake and reported it immediately. That is what responsible conduct looks like.
Analyzeこれほど厳しい条件で目標を達成したのは、見事というものです。
Achieving the goal under such difficult conditions is truly impressive.
Analyze何も聞かずに決めつけるなんて、失礼ってもんだよ。
Making assumptions without even asking is just rude.
AnalyzeThis uses the conversational contraction.