で言うsyntax in context

Question

最近は「アイデンティティ」とか「コンプライアンス」などのことばも使われている。日本語でうまく言えないから、使われるのかもしれない。しかし、日本語で言えるのに、外来語を使うのは問題だ。例えば、よく「ポリシー」と言う人がいるが、「考え方」とか「やり方」と言ったほうがずっと正確でわかりやすい場合が多い。

I know that 日本語で言える means something along "...you can say it in Japanese". I just think I'm missing the subject in the bolt sentence and its connection with the form "で言う", as he changes from potential (言える) to passive (使われる). This mitigates also to the next sentence, so in total I would interpret this and the following passage like:

Since I(?)/people(?) can't say (these words) properly in Japanese, they might be used (in Katakana form). But when one can say them in Japanese, using foreign words is a problem. For example, there are people that often say "policy" but, rather saying "考え方” or "やり方”, is much more accurate and easily understood in most cases.

Answer 1

日本語で言える may usually be translated as "I/you/somebody can say it in Japanese," but it could also be translated as "It can be said in Japanese." After all, を changes to が for both passive and potential conjugations (usually).

日本語でうまく言えないから、使われるのかもしれない。
Maybe (literally: it can't be known if) they are used because they (the words) can't be said well in Japanese.

Then it goes on to say, "However, using foreign/imported words even when they can be said in Japanese is a problem."

Answer 2

The subject of this sentence is

（人々は／私たちは）日本語でうまく言えないから、（それらが／カタカナ言葉が／横文字｛よこもじ｝が）使われるのかもしれない。

The translation wouldn't be "Since I can't say" because 使う is in the passive form 使われる, which kind of gives the nuance of generally being used by many people.

If the subject is I, then I'd say

日本語でうまくいえないから、使うのかもしれない。