ものだ expressing ambiguous emotions/concern?


[This](https://www.wasabi-jpn.com/japanese-grammar/part-of-speech/japanese-
interjection-and-emotional-expressions/) article lists many examples of using
ものだ to articulate "deep concern." The author of this article explains that
when you connect words which indicate desire like …たい and 欲しい with ものだ, your
speech indicates hope with some concerns.

For instance:

> 「次の大統領は優秀な人になってもらいたい（もんだ / ものだ）。」

Translated as: As for the next president, [I] would like a prominent person to
be elected.

The nuance in this sentence was explained as "The current one (president)
isn’t good, so you’re expecting the next one with frustration.”

> 「こういう服を一度着てみたい（もんだ / ものだ）。」

I] want to try to wear clothing like this once [in my life]. *You long for
wearing it, but are resigned to wear it at the same time.

Earlier in the article the author explains that "the combination between
predicates and ものだ or ことだ determines the nuances. When you connect words which
indicate change of things or people with ものだ, your speech indicates
inexpressible deep emotion. In general, the emotion is not expressively told.
You need to guess it."

Does this explanation explain why combinations of words linked to desire
combined with ものだ automatically signal concern within hope? I'm a little
confused about why concern is the thing that is signaled in this kind of
construction.




In my understanding the purpose behind saying ...ものだ is for the speaker to
express their belief that "..." is something everyone would agree upon,
something without question, something objectively obvious.

This underlying meaning _could be_ used to express hope or concern as in your
examples, but I think it is more the content of the thought rather than the
usage of ...ものだ that indicates this.

> 「こういう服を一度着てみたい（もんだ / ものだ）。」

_The speaker believes_ that it is **inherently obvious** that "this kind of
clothing" is something that one would "want to try on once"

> 「次の大統領は優秀な人になってもらいたい（もんだ / ものだ）。」

_The speaker believes_ that it is **inherently obvious** that **anyone would
agree with him** in desiring the next President to be an exceptional person

四 （形式名詞） Definitions 1 and 2 at the link below:

<https://www.weblio.jp/content/%E3%82%82%E3%81%AE>

