I think I know why you do not think this sentence makes sense. (The sentence makes perfect sense, I assure you.)
「～～からである」 indeed expresses the reason for a result (or the cause of an effect), but you are looking for the description of the result/effect within that one sentence, are you not? If so, the result/effect is not mentioned within the sentence. It should be mentioned in the preceding sentences.
"That is because the yen was accelerating its appreciation in order to stop Japanese export business."
The same thing could be said about your second example sentence. The result/effect is not mentioned in it.
"That is because the prices, except for land prices, had become stabilized as well."