Translation:Because he is clean, he is nice.
The problem is that it isn't indicated that they are synonyms. (if and when they are)
Puisque and depuis were introduced in the same manner as if they were likely synonyms. But a poster on another tread indicates that they are not synonyms but involve different uses of since specifically relating to time or causation. (My words not his).
Du fait que is yet another unexplained instance of since presented as if it was simply another construction similar in every respect to previous examples of since . It may well be such but we have no way of knowing whether that is true.
A student of Duo seeing them all presented as if they were interchangeable could get a correct answer and proceed as if he understood their correct usage when he actually didn't.
"puisque" is definitely causal and no temporal, same family of causal conjunctions as "du fait que" or "parce que"
"depuis que" is definitely temporal and not causal, same family of temporal conjunctions as "quand", "après que", "avant que", "dès que" (+ others, like "à partir du moment où", "du moment où"...)